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OESA-2026-2681 (CVE-2026-50256)

Vulnerability from osv_openeuler – Published: 2026-06-12 11:11 – Updated: 2026-08-06 11:11 – Source website
VLAI
Summary
xorg-x11-server security update
Details

X.Org X11 X server

Security Fix(es):

['Hi all,\n\nCVEs have been issued now, please see inline below\n\nOn Tue, Jun 02, 2026 at 10:01:46AM +1000, Peter Hutterer wrote:', "=======================================================================\nX.Org Security Advisory: June 2, 2026 \n\nIssues in X.Org X server prior to 21.1.23 and Xwayland prior to 24.1.12\n=======================================================================\n\nMultiple issues have been found in the X server and Xwayland implementations\npublished by X.Org for which we are releasing security fixes for in\nxorg-server-21.1.23 and xwayland-24.1.12.\n\nNote that CVEs have been requested for these issues but did not get assigned in\ntime for this disclosure.\n\n Font Alias Stack-based Buffer Overflow\n\n A mismatch between the X server and the libXfont2 library's maximum\n font name length can cause a stack buffer overflow during font alias\n resolution. The server allocates a 256 byte stack buffer but libXfont2's\n alias target name length is 1024 bytes. A font alias name between 257\n and 1023 bytes causes the X server to copy that name into the undersized\n stack buffer without further checks.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:", 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30136)', 'This issue has been assigned CVE-2026-50256', ' XSYNC Use-After-Free in miSyncDestroyFence()\n\n A client that sets up multiple fence triggers can trigger a\n use-after-free function pointer call. An attacker would connect to the\n X server to set up a fence and await that fence, then a second X\n connection destroys the fence, causing the use-after-free.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30159)', 'This issue has been assigned CVE-2026-50257', ' XKB Key Types Stack-based Buffer Overflow\n\n The X server has multiple stack buffers that are sized\n XkbMaxShiftLevel * XkbNumKbdGroups but CheckKeyTypes() does not verify\n or clamp non-canonical key types to XkbMaxShiftLevel. A client can\n change key types to excessive shift levels and trigger three separate\n stack overflows.\n\n This is caused by an incomplete fix of CVE-2025-26597.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30160)', 'This issue has been assigned CVE-2026-50258', ' XKB SetMap Request Stack-based Buffer Overflow\n\n _XkbSetMapChecks() declares a fixed-size stack buffer mapWidths[256]\n indexed by key type index. The helper function CheckKeyTypes() writes\n to this buffer at a client-controlled offset, allowing a stack buffer\n overflow.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30161)', 'This issue has been assigned CVE-2026-50259', ' XSYNC Use-After-Free in FreeCounter()\n\n A client that sets up multiple SyncCounters and awaits on those\n triggers can trigger a use-after-free when destroying those counters\n via a second client connection.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30163)', 'This issue has been assigned CVE-2026-50260', ' XSYNC Use-After-Free in SyncChangeCounter()\n\n A client that sets up multiple SyncCounters can trigger a use-after-free\n when destroying those counters via a second client connection while\n changing those counters.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30164)', 'This issue has been assigned CVE-2026-50261', '* GLX ChangeDrawableAttributes Out-Of-Bounds Read/Write\n\n A wrong size validation check in __glXDisp_ChangeDrawableAttributes()\n can read (or write) a client-contr(CVE-2026-50256)

['Hi all,\n\nCVEs have been issued now, please see inline below\n\nOn Tue, Jun 02, 2026 at 10:01:46AM +1000, Peter Hutterer wrote:', "=======================================================================\nX.Org Security Advisory: June 2, 2026 \n\nIssues in X.Org X server prior to 21.1.23 and Xwayland prior to 24.1.12\n=======================================================================\n\nMultiple issues have been found in the X server and Xwayland implementations\npublished by X.Org for which we are releasing security fixes for in\nxorg-server-21.1.23 and xwayland-24.1.12.\n\nNote that CVEs have been requested for these issues but did not get assigned in\ntime for this disclosure.\n\n Font Alias Stack-based Buffer Overflow\n\n A mismatch between the X server and the libXfont2 library's maximum\n font name length can cause a stack buffer overflow during font alias\n resolution. The server allocates a 256 byte stack buffer but libXfont2's\n alias target name length is 1024 bytes. A font alias name between 257\n and 1023 bytes causes the X server to copy that name into the undersized\n stack buffer without further checks.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:", 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30136)', 'This issue has been assigned CVE-2026-50256', ' XSYNC Use-After-Free in miSyncDestroyFence()\n\n A client that sets up multiple fence triggers can trigger a\n use-after-free function pointer call. An attacker would connect to the\n X server to set up a fence and await that fence, then a second X\n connection destroys the fence, causing the use-after-free.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30159)', 'This issue has been assigned CVE-2026-50257', ' XKB Key Types Stack-based Buffer Overflow\n\n The X server has multiple stack buffers that are sized\n XkbMaxShiftLevel * XkbNumKbdGroups but CheckKeyTypes() does not verify\n or clamp non-canonical key types to XkbMaxShiftLevel. A client can\n change key types to excessive shift levels and trigger three separate\n stack overflows.\n\n This is caused by an incomplete fix of CVE-2025-26597.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30160)', 'This issue has been assigned CVE-2026-50258', ' XKB SetMap Request Stack-based Buffer Overflow\n\n _XkbSetMapChecks() declares a fixed-size stack buffer mapWidths[256]\n indexed by key type index. The helper function CheckKeyTypes() writes\n to this buffer at a client-controlled offset, allowing a stack buffer\n overflow.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30161)', 'This issue has been assigned CVE-2026-50259', ' XSYNC Use-After-Free in FreeCounter()\n\n A client that sets up multiple SyncCounters and awaits on those\n triggers can trigger a use-after-free when destroying those counters\n via a second client connection.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30163)', 'This issue has been assigned CVE-2026-50260', ' XSYNC Use-After-Free in SyncChangeCounter()\n\n A client that sets up multiple SyncCounters can trigger a use-after-free\n when destroying those counters via a second client connection while\n changing those counters.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30164)', 'This issue has been assigned CVE-2026-50261', '* GLX ChangeDrawableAttributes Out-Of-Bounds Read/Write\n\n A wrong size validation check in __glXDisp_ChangeDrawableAttributes()\n can read (or write) a client-contr(CVE-2026-50257)

['Hi all,\n\nCVEs have been issued now, please see inline below\n\nOn Tue, Jun 02, 2026 at 10:01:46AM +1000, Peter Hutterer wrote:', "=======================================================================\nX.Org Security Advisory: June 2, 2026 \n\nIssues in X.Org X server prior to 21.1.23 and Xwayland prior to 24.1.12\n=======================================================================\n\nMultiple issues have been found in the X server and Xwayland implementations\npublished by X.Org for which we are releasing security fixes for in\nxorg-server-21.1.23 and xwayland-24.1.12.\n\nNote that CVEs have been requested for these issues but did not get assigned in\ntime for this disclosure.\n\n Font Alias Stack-based Buffer Overflow\n\n A mismatch between the X server and the libXfont2 library's maximum\n font name length can cause a stack buffer overflow during font alias\n resolution. The server allocates a 256 byte stack buffer but libXfont2's\n alias target name length is 1024 bytes. A font alias name between 257\n and 1023 bytes causes the X server to copy that name into the undersized\n stack buffer without further checks.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:", 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30136)', 'This issue has been assigned CVE-2026-50256', ' XSYNC Use-After-Free in miSyncDestroyFence()\n\n A client that sets up multiple fence triggers can trigger a\n use-after-free function pointer call. An attacker would connect to the\n X server to set up a fence and await that fence, then a second X\n connection destroys the fence, causing the use-after-free.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30159)', 'This issue has been assigned CVE-2026-50257', ' XKB Key Types Stack-based Buffer Overflow\n\n The X server has multiple stack buffers that are sized\n XkbMaxShiftLevel * XkbNumKbdGroups but CheckKeyTypes() does not verify\n or clamp non-canonical key types to XkbMaxShiftLevel. A client can\n change key types to excessive shift levels and trigger three separate\n stack overflows.\n\n This is caused by an incomplete fix of CVE-2025-26597.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30160)', 'This issue has been assigned CVE-2026-50258', ' XKB SetMap Request Stack-based Buffer Overflow\n\n _XkbSetMapChecks() declares a fixed-size stack buffer mapWidths[256]\n indexed by key type index. The helper function CheckKeyTypes() writes\n to this buffer at a client-controlled offset, allowing a stack buffer\n overflow.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30161)', 'This issue has been assigned CVE-2026-50259', ' XSYNC Use-After-Free in FreeCounter()\n\n A client that sets up multiple SyncCounters and awaits on those\n triggers can trigger a use-after-free when destroying those counters\n via a second client connection.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30163)', 'This issue has been assigned CVE-2026-50260', ' XSYNC Use-After-Free in SyncChangeCounter()\n\n A client that sets up multiple SyncCounters can trigger a use-after-free\n when destroying those counters via a second client connection while\n changing those counters.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30164)', 'This issue has been assigned CVE-2026-50261', '* GLX ChangeDrawableAttributes Out-Of-Bounds Read/Write\n\n A wrong size validation check in __glXDisp_ChangeDrawableAttributes()\n can read (or write) a client-contr(CVE-2026-50258)

['Hi all,\n\nCVEs have been issued now, please see inline below\n\nOn Tue, Jun 02, 2026 at 10:01:46AM +1000, Peter Hutterer wrote:', "=======================================================================\nX.Org Security Advisory: June 2, 2026 \n\nIssues in X.Org X server prior to 21.1.23 and Xwayland prior to 24.1.12\n=======================================================================\n\nMultiple issues have been found in the X server and Xwayland implementations\npublished by X.Org for which we are releasing security fixes for in\nxorg-server-21.1.23 and xwayland-24.1.12.\n\nNote that CVEs have been requested for these issues but did not get assigned in\ntime for this disclosure.\n\n Font Alias Stack-based Buffer Overflow\n\n A mismatch between the X server and the libXfont2 library's maximum\n font name length can cause a stack buffer overflow during font alias\n resolution. The server allocates a 256 byte stack buffer but libXfont2's\n alias target name length is 1024 bytes. A font alias name between 257\n and 1023 bytes causes the X server to copy that name into the undersized\n stack buffer without further checks.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:", 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30136)', 'This issue has been assigned CVE-2026-50256', ' XSYNC Use-After-Free in miSyncDestroyFence()\n\n A client that sets up multiple fence triggers can trigger a\n use-after-free function pointer call. An attacker would connect to the\n X server to set up a fence and await that fence, then a second X\n connection destroys the fence, causing the use-after-free.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30159)', 'This issue has been assigned CVE-2026-50257', ' XKB Key Types Stack-based Buffer Overflow\n\n The X server has multiple stack buffers that are sized\n XkbMaxShiftLevel * XkbNumKbdGroups but CheckKeyTypes() does not verify\n or clamp non-canonical key types to XkbMaxShiftLevel. A client can\n change key types to excessive shift levels and trigger three separate\n stack overflows.\n\n This is caused by an incomplete fix of CVE-2025-26597.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30160)', 'This issue has been assigned CVE-2026-50258', ' XKB SetMap Request Stack-based Buffer Overflow\n\n _XkbSetMapChecks() declares a fixed-size stack buffer mapWidths[256]\n indexed by key type index. The helper function CheckKeyTypes() writes\n to this buffer at a client-controlled offset, allowing a stack buffer\n overflow.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30161)', 'This issue has been assigned CVE-2026-50259', ' XSYNC Use-After-Free in FreeCounter()\n\n A client that sets up multiple SyncCounters and awaits on those\n triggers can trigger a use-after-free when destroying those counters\n via a second client connection.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30163)', 'This issue has been assigned CVE-2026-50260', ' XSYNC Use-After-Free in SyncChangeCounter()\n\n A client that sets up multiple SyncCounters can trigger a use-after-free\n when destroying those counters via a second client connection while\n changing those counters.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30164)', 'This issue has been assigned CVE-2026-50261', '* GLX ChangeDrawableAttributes Out-Of-Bounds Read/Write\n\n A wrong size validation check in __glXDisp_ChangeDrawableAttributes()\n can read (or write) a client-contr(CVE-2026-50259)

A use-after-free flaw was found in the X.Org X server and Xwayland in FreeCounter(). A client that sets up multiple SyncCounters and awaits on those triggers can trigger a use-after-free when destroying those counters via a second client connection. This may be used to crash the server, or for privilege escalation if the X server runs as root.(CVE-2026-50260)

A use-after-free flaw was found in the X.Org X server and Xwayland in SyncChangeCounter(). A client that sets up multiple SyncCounters can trigger a use-after-free when destroying those counters via a second client connection while changing those counters. This may be used to crash the server, or for privilege escalation if the X server runs as root.(CVE-2026-50261)

An out-of-bounds read flaw was found in the X.Org X server and Xwayland in __glXDisp_ChangeDrawableAttributes(). A wrong size validation check can read a client-controlled number of bytes, exceeding the request buffer, leading to information disclosure. A write path also exists but requires byte-swapped clients which is disabled by default.(CVE-2026-50262)

['Hi all,\n\nCVEs have been issued now, please see inline below\n\nOn Tue, Jun 02, 2026 at 10:01:46AM +1000, Peter Hutterer wrote:', "=======================================================================\nX.Org Security Advisory: June 2, 2026 \n\nIssues in X.Org X server prior to 21.1.23 and Xwayland prior to 24.1.12\n=======================================================================\n\nMultiple issues have been found in the X server and Xwayland implementations\npublished by X.Org for which we are releasing security fixes for in\nxorg-server-21.1.23 and xwayland-24.1.12.\n\nNote that CVEs have been requested for these issues but did not get assigned in\ntime for this disclosure.\n\n Font Alias Stack-based Buffer Overflow\n\n A mismatch between the X server and the libXfont2 library's maximum\n font name length can cause a stack buffer overflow during font alias\n resolution. The server allocates a 256 byte stack buffer but libXfont2's\n alias target name length is 1024 bytes. A font alias name between 257\n and 1023 bytes causes the X server to copy that name into the undersized\n stack buffer without further checks.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:", 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30136)', 'This issue has been assigned CVE-2026-50256', ' XSYNC Use-After-Free in miSyncDestroyFence()\n\n A client that sets up multiple fence triggers can trigger a\n use-after-free function pointer call. An attacker would connect to the\n X server to set up a fence and await that fence, then a second X\n connection destroys the fence, causing the use-after-free.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30159)', 'This issue has been assigned CVE-2026-50257', ' XKB Key Types Stack-based Buffer Overflow\n\n The X server has multiple stack buffers that are sized\n XkbMaxShiftLevel * XkbNumKbdGroups but CheckKeyTypes() does not verify\n or clamp non-canonical key types to XkbMaxShiftLevel. A client can\n change key types to excessive shift levels and trigger three separate\n stack overflows.\n\n This is caused by an incomplete fix of CVE-2025-26597.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30160)', 'This issue has been assigned CVE-2026-50258', ' XKB SetMap Request Stack-based Buffer Overflow\n\n _XkbSetMapChecks() declares a fixed-size stack buffer mapWidths[256]\n indexed by key type index. The helper function CheckKeyTypes() writes\n to this buffer at a client-controlled offset, allowing a stack buffer\n overflow.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30161)', 'This issue has been assigned CVE-2026-50259', ' XSYNC Use-After-Free in FreeCounter()\n\n A client that sets up multiple SyncCounters and awaits on those\n triggers can trigger a use-after-free when destroying those counters\n via a second client connection.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30163)', 'This issue has been assigned CVE-2026-50260', ' XSYNC Use-After-Free in SyncChangeCounter()\n\n A client that sets up multiple SyncCounters can trigger a use-after-free\n when destroying those counters via a second client connection while\n changing those counters.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30164)', 'This issue has been assigned CVE-2026-50261', '* GLX ChangeDrawableAttributes Out-Of-Bounds Read/Write\n\n A wrong size validation check in __glXDisp_ChangeDrawableAttributes()\n can read (or write) a client-contr(CVE-2026-50263)

An out-of-bounds write flaw was found in the X.Org X server and Xwayland in DRIGetBuffers/DRIGetBuffersWithFormat. A client that requests multiple DRI2BufferBackLeft attachments and one DRI2BufferFrontLeft can trigger an out-of-bounds heap write. This may be used to crash the server, or for privilege escalation if the X server runs as root.(CVE-2026-50264)

Severity
7.8 (High)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
References
To clipboard 

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  "database_specific": {
    "severity": "High"
  },
  "details": "X.Org X11 X server\r\n\r\nSecurity Fix(es):\n\n[\u0026apos;Hi all,\\n\\nCVEs have been issued now, please see inline below\\n\\nOn Tue, Jun 02, 2026 at 10:01:46AM +1000, Peter Hutterer wrote:\u0026apos;, \u0026quot;=======================================================================\\nX.Org Security Advisory: June 2, 2026 \\n\\nIssues in X.Org X server prior to 21.1.23 and Xwayland prior to 24.1.12\\n=======================================================================\\n\\nMultiple issues have been found in the X server and Xwayland implementations\\npublished by X.Org for which we are releasing security fixes for in\\nxorg-server-21.1.23 and xwayland-24.1.12.\\n\\nNote that CVEs have been requested for these issues but did not get assigned in\\ntime for this disclosure.\\n\\n* Font Alias Stack-based Buffer Overflow\\n\\n    A mismatch between the X server and the libXfont2 library\u0026apos;s maximum\\n    font name length can cause a stack buffer overflow during font alias\\n    resolution. The server allocates a 256 byte stack buffer but libXfont2\u0026apos;s\\n    alias target name length is 1024 bytes. A font alias name between 257\\n    and 1023 bytes causes the X server to copy that name into the undersized\\n    stack buffer without further checks.\\n\\n    Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\\n    Fix:\u0026quot;, \u0026apos;Found by: Anonymous working with TrendAI Zero Day Initiative.\\n              (ZDI-CAN-30136)\u0026apos;, \u0026apos;This issue has been assigned CVE-2026-50256\u0026apos;, \u0026apos;* XSYNC Use-After-Free in miSyncDestroyFence()\\n\\n    A client that sets up multiple fence triggers can trigger a\\n    use-after-free function pointer call. An attacker would connect to the\\n    X server to set up a fence and await that fence, then a second X\\n    connection destroys the fence, causing the use-after-free.\\n\\n    Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\\n    Fix:\u0026apos;, \u0026apos;Found by: Anonymous working with TrendAI Zero Day Initiative.\\n              (ZDI-CAN-30159)\u0026apos;, \u0026apos;This issue has been assigned CVE-2026-50257\u0026apos;, \u0026apos;* XKB Key Types Stack-based Buffer Overflow\\n\\n    The X server has multiple stack buffers that are sized\\n    XkbMaxShiftLevel * XkbNumKbdGroups but CheckKeyTypes() does not verify\\n    or clamp non-canonical key types to XkbMaxShiftLevel. A client can\\n    change key types to excessive shift levels and trigger three separate\\n    stack overflows.\\n\\n    This is caused by an incomplete fix of CVE-2025-26597.\\n\\n    Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\\n    Fix:\u0026apos;, \u0026apos;Found by: Anonymous working with TrendAI Zero Day Initiative.\\n              (ZDI-CAN-30160)\u0026apos;, \u0026apos;This issue has been assigned CVE-2026-50258\u0026apos;, \u0026apos;* XKB SetMap Request Stack-based Buffer Overflow\\n\\n    _XkbSetMapChecks() declares a fixed-size stack buffer mapWidths[256]\\n    indexed by key type index. The helper function CheckKeyTypes() writes\\n    to this buffer at a client-controlled offset, allowing a stack buffer\\n    overflow.\\n\\n    Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\\n    Fix:\u0026apos;, \u0026apos;Found by: Anonymous working with TrendAI Zero Day Initiative.\\n              (ZDI-CAN-30161)\u0026apos;, \u0026apos;This issue has been assigned CVE-2026-50259\u0026apos;, \u0026apos;* XSYNC Use-After-Free in FreeCounter()\\n\\n    A client that sets up multiple SyncCounters and awaits on those\\n    triggers can trigger a use-after-free when destroying those counters\\n    via a second client connection.\\n\\n    Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\\n    Fix:\u0026apos;, \u0026apos;Found by: Anonymous working with TrendAI Zero Day Initiative.\\n              (ZDI-CAN-30163)\u0026apos;, \u0026apos;This issue has been assigned CVE-2026-50260\u0026apos;, \u0026apos;* XSYNC Use-After-Free in SyncChangeCounter()\\n\\n    A client that sets up multiple SyncCounters can trigger a use-after-free\\n    when destroying those counters via a second client connection while\\n    changing those counters.\\n\\n    Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\\n    Fix:\u0026apos;, \u0026apos;Found by: Anonymous working with TrendAI Zero Day Initiative.\\n              (ZDI-CAN-30164)\u0026apos;, \u0026apos;This issue has been assigned CVE-2026-50261\u0026apos;, \u0026apos;* GLX ChangeDrawableAttributes Out-Of-Bounds Read/Write\\n\\n    A wrong size validation check in __glXDisp_ChangeDrawableAttributes()\\n    can read (or write) a client-contr(CVE-2026-50256)\n\n[\u0026apos;Hi all,\\n\\nCVEs have been issued now, please see inline below\\n\\nOn Tue, Jun 02, 2026 at 10:01:46AM +1000, Peter Hutterer wrote:\u0026apos;, \u0026quot;=======================================================================\\nX.Org Security Advisory: June 2, 2026 \\n\\nIssues in X.Org X server prior to 21.1.23 and Xwayland prior to 24.1.12\\n=======================================================================\\n\\nMultiple issues have been found in the X server and Xwayland implementations\\npublished by X.Org for which we are releasing security fixes for in\\nxorg-server-21.1.23 and xwayland-24.1.12.\\n\\nNote that CVEs have been requested for these issues but did not get assigned in\\ntime for this disclosure.\\n\\n* Font Alias Stack-based Buffer Overflow\\n\\n    A mismatch between the X server and the libXfont2 library\u0026apos;s maximum\\n    font name length can cause a stack buffer overflow during font alias\\n    resolution. The server allocates a 256 byte stack buffer but libXfont2\u0026apos;s\\n    alias target name length is 1024 bytes. A font alias name between 257\\n    and 1023 bytes causes the X server to copy that name into the undersized\\n    stack buffer without further checks.\\n\\n    Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\\n    Fix:\u0026quot;, \u0026apos;Found by: Anonymous working with TrendAI Zero Day Initiative.\\n              (ZDI-CAN-30136)\u0026apos;, \u0026apos;This issue has been assigned CVE-2026-50256\u0026apos;, \u0026apos;* XSYNC Use-After-Free in miSyncDestroyFence()\\n\\n    A client that sets up multiple fence triggers can trigger a\\n    use-after-free function pointer call. An attacker would connect to the\\n    X server to set up a fence and await that fence, then a second X\\n    connection destroys the fence, causing the use-after-free.\\n\\n    Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\\n    Fix:\u0026apos;, \u0026apos;Found by: Anonymous working with TrendAI Zero Day Initiative.\\n              (ZDI-CAN-30159)\u0026apos;, \u0026apos;This issue has been assigned CVE-2026-50257\u0026apos;, \u0026apos;* XKB Key Types Stack-based Buffer Overflow\\n\\n    The X server has multiple stack buffers that are sized\\n    XkbMaxShiftLevel * XkbNumKbdGroups but CheckKeyTypes() does not verify\\n    or clamp non-canonical key types to XkbMaxShiftLevel. A client can\\n    change key types to excessive shift levels and trigger three separate\\n    stack overflows.\\n\\n    This is caused by an incomplete fix of CVE-2025-26597.\\n\\n    Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\\n    Fix:\u0026apos;, \u0026apos;Found by: Anonymous working with TrendAI Zero Day Initiative.\\n              (ZDI-CAN-30160)\u0026apos;, \u0026apos;This issue has been assigned CVE-2026-50258\u0026apos;, \u0026apos;* XKB SetMap Request Stack-based Buffer Overflow\\n\\n    _XkbSetMapChecks() declares a fixed-size stack buffer mapWidths[256]\\n    indexed by key type index. The helper function CheckKeyTypes() writes\\n    to this buffer at a client-controlled offset, allowing a stack buffer\\n    overflow.\\n\\n    Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\\n    Fix:\u0026apos;, \u0026apos;Found by: Anonymous working with TrendAI Zero Day Initiative.\\n              (ZDI-CAN-30161)\u0026apos;, \u0026apos;This issue has been assigned CVE-2026-50259\u0026apos;, \u0026apos;* XSYNC Use-After-Free in FreeCounter()\\n\\n    A client that sets up multiple SyncCounters and awaits on those\\n    triggers can trigger a use-after-free when destroying those counters\\n    via a second client connection.\\n\\n    Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\\n    Fix:\u0026apos;, \u0026apos;Found by: Anonymous working with TrendAI Zero Day Initiative.\\n              (ZDI-CAN-30163)\u0026apos;, \u0026apos;This issue has been assigned CVE-2026-50260\u0026apos;, \u0026apos;* XSYNC Use-After-Free in SyncChangeCounter()\\n\\n    A client that sets up multiple SyncCounters can trigger a use-after-free\\n    when destroying those counters via a second client connection while\\n    changing those counters.\\n\\n    Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\\n    Fix:\u0026apos;, \u0026apos;Found by: Anonymous working with TrendAI Zero Day Initiative.\\n              (ZDI-CAN-30164)\u0026apos;, \u0026apos;This issue has been assigned CVE-2026-50261\u0026apos;, \u0026apos;* GLX ChangeDrawableAttributes Out-Of-Bounds Read/Write\\n\\n    A wrong size validation check in __glXDisp_ChangeDrawableAttributes()\\n    can read (or write) a client-contr(CVE-2026-50257)\n\n[\u0026apos;Hi all,\\n\\nCVEs have been issued now, please see inline below\\n\\nOn Tue, Jun 02, 2026 at 10:01:46AM +1000, Peter Hutterer wrote:\u0026apos;, \u0026quot;=======================================================================\\nX.Org Security Advisory: June 2, 2026 \\n\\nIssues in X.Org X server prior to 21.1.23 and Xwayland prior to 24.1.12\\n=======================================================================\\n\\nMultiple issues have been found in the X server and Xwayland implementations\\npublished by X.Org for which we are releasing security fixes for in\\nxorg-server-21.1.23 and xwayland-24.1.12.\\n\\nNote that CVEs have been requested for these issues but did not get assigned in\\ntime for this disclosure.\\n\\n* Font Alias Stack-based Buffer Overflow\\n\\n    A mismatch between the X server and the libXfont2 library\u0026apos;s maximum\\n    font name length can cause a stack buffer overflow during font alias\\n    resolution. The server allocates a 256 byte stack buffer but libXfont2\u0026apos;s\\n    alias target name length is 1024 bytes. A font alias name between 257\\n    and 1023 bytes causes the X server to copy that name into the undersized\\n    stack buffer without further checks.\\n\\n    Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\\n    Fix:\u0026quot;, \u0026apos;Found by: Anonymous working with TrendAI Zero Day Initiative.\\n              (ZDI-CAN-30136)\u0026apos;, \u0026apos;This issue has been assigned CVE-2026-50256\u0026apos;, \u0026apos;* XSYNC Use-After-Free in miSyncDestroyFence()\\n\\n    A client that sets up multiple fence triggers can trigger a\\n    use-after-free function pointer call. An attacker would connect to the\\n    X server to set up a fence and await that fence, then a second X\\n    connection destroys the fence, causing the use-after-free.\\n\\n    Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\\n    Fix:\u0026apos;, \u0026apos;Found by: Anonymous working with TrendAI Zero Day Initiative.\\n              (ZDI-CAN-30159)\u0026apos;, \u0026apos;This issue has been assigned CVE-2026-50257\u0026apos;, \u0026apos;* XKB Key Types Stack-based Buffer Overflow\\n\\n    The X server has multiple stack buffers that are sized\\n    XkbMaxShiftLevel * XkbNumKbdGroups but CheckKeyTypes() does not verify\\n    or clamp non-canonical key types to XkbMaxShiftLevel. A client can\\n    change key types to excessive shift levels and trigger three separate\\n    stack overflows.\\n\\n    This is caused by an incomplete fix of CVE-2025-26597.\\n\\n    Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\\n    Fix:\u0026apos;, \u0026apos;Found by: Anonymous working with TrendAI Zero Day Initiative.\\n              (ZDI-CAN-30160)\u0026apos;, \u0026apos;This issue has been assigned CVE-2026-50258\u0026apos;, \u0026apos;* XKB SetMap Request Stack-based Buffer Overflow\\n\\n    _XkbSetMapChecks() declares a fixed-size stack buffer mapWidths[256]\\n    indexed by key type index. The helper function CheckKeyTypes() writes\\n    to this buffer at a client-controlled offset, allowing a stack buffer\\n    overflow.\\n\\n    Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\\n    Fix:\u0026apos;, \u0026apos;Found by: Anonymous working with TrendAI Zero Day Initiative.\\n              (ZDI-CAN-30161)\u0026apos;, \u0026apos;This issue has been assigned CVE-2026-50259\u0026apos;, \u0026apos;* XSYNC Use-After-Free in FreeCounter()\\n\\n    A client that sets up multiple SyncCounters and awaits on those\\n    triggers can trigger a use-after-free when destroying those counters\\n    via a second client connection.\\n\\n    Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\\n    Fix:\u0026apos;, \u0026apos;Found by: Anonymous working with TrendAI Zero Day Initiative.\\n              (ZDI-CAN-30163)\u0026apos;, \u0026apos;This issue has been assigned CVE-2026-50260\u0026apos;, \u0026apos;* XSYNC Use-After-Free in SyncChangeCounter()\\n\\n    A client that sets up multiple SyncCounters can trigger a use-after-free\\n    when destroying those counters via a second client connection while\\n    changing those counters.\\n\\n    Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\\n    Fix:\u0026apos;, \u0026apos;Found by: Anonymous working with TrendAI Zero Day Initiative.\\n              (ZDI-CAN-30164)\u0026apos;, \u0026apos;This issue has been assigned CVE-2026-50261\u0026apos;, \u0026apos;* GLX ChangeDrawableAttributes Out-Of-Bounds Read/Write\\n\\n    A wrong size validation check in __glXDisp_ChangeDrawableAttributes()\\n    can read (or write) a client-contr(CVE-2026-50258)\n\n[\u0026apos;Hi all,\\n\\nCVEs have been issued now, please see inline below\\n\\nOn Tue, Jun 02, 2026 at 10:01:46AM +1000, Peter Hutterer wrote:\u0026apos;, \u0026quot;=======================================================================\\nX.Org Security Advisory: June 2, 2026 \\n\\nIssues in X.Org X server prior to 21.1.23 and Xwayland prior to 24.1.12\\n=======================================================================\\n\\nMultiple issues have been found in the X server and Xwayland implementations\\npublished by X.Org for which we are releasing security fixes for in\\nxorg-server-21.1.23 and xwayland-24.1.12.\\n\\nNote that CVEs have been requested for these issues but did not get assigned in\\ntime for this disclosure.\\n\\n* Font Alias Stack-based Buffer Overflow\\n\\n    A mismatch between the X server and the libXfont2 library\u0026apos;s maximum\\n    font name length can cause a stack buffer overflow during font alias\\n    resolution. The server allocates a 256 byte stack buffer but libXfont2\u0026apos;s\\n    alias target name length is 1024 bytes. A font alias name between 257\\n    and 1023 bytes causes the X server to copy that name into the undersized\\n    stack buffer without further checks.\\n\\n    Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\\n    Fix:\u0026quot;, \u0026apos;Found by: Anonymous working with TrendAI Zero Day Initiative.\\n              (ZDI-CAN-30136)\u0026apos;, \u0026apos;This issue has been assigned CVE-2026-50256\u0026apos;, \u0026apos;* XSYNC Use-After-Free in miSyncDestroyFence()\\n\\n    A client that sets up multiple fence triggers can trigger a\\n    use-after-free function pointer call. An attacker would connect to the\\n    X server to set up a fence and await that fence, then a second X\\n    connection destroys the fence, causing the use-after-free.\\n\\n    Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\\n    Fix:\u0026apos;, \u0026apos;Found by: Anonymous working with TrendAI Zero Day Initiative.\\n              (ZDI-CAN-30159)\u0026apos;, \u0026apos;This issue has been assigned CVE-2026-50257\u0026apos;, \u0026apos;* XKB Key Types Stack-based Buffer Overflow\\n\\n    The X server has multiple stack buffers that are sized\\n    XkbMaxShiftLevel * XkbNumKbdGroups but CheckKeyTypes() does not verify\\n    or clamp non-canonical key types to XkbMaxShiftLevel. A client can\\n    change key types to excessive shift levels and trigger three separate\\n    stack overflows.\\n\\n    This is caused by an incomplete fix of CVE-2025-26597.\\n\\n    Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\\n    Fix:\u0026apos;, \u0026apos;Found by: Anonymous working with TrendAI Zero Day Initiative.\\n              (ZDI-CAN-30160)\u0026apos;, \u0026apos;This issue has been assigned CVE-2026-50258\u0026apos;, \u0026apos;* XKB SetMap Request Stack-based Buffer Overflow\\n\\n    _XkbSetMapChecks() declares a fixed-size stack buffer mapWidths[256]\\n    indexed by key type index. The helper function CheckKeyTypes() writes\\n    to this buffer at a client-controlled offset, allowing a stack buffer\\n    overflow.\\n\\n    Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\\n    Fix:\u0026apos;, \u0026apos;Found by: Anonymous working with TrendAI Zero Day Initiative.\\n              (ZDI-CAN-30161)\u0026apos;, \u0026apos;This issue has been assigned CVE-2026-50259\u0026apos;, \u0026apos;* XSYNC Use-After-Free in FreeCounter()\\n\\n    A client that sets up multiple SyncCounters and awaits on those\\n    triggers can trigger a use-after-free when destroying those counters\\n    via a second client connection.\\n\\n    Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\\n    Fix:\u0026apos;, \u0026apos;Found by: Anonymous working with TrendAI Zero Day Initiative.\\n              (ZDI-CAN-30163)\u0026apos;, \u0026apos;This issue has been assigned CVE-2026-50260\u0026apos;, \u0026apos;* XSYNC Use-After-Free in SyncChangeCounter()\\n\\n    A client that sets up multiple SyncCounters can trigger a use-after-free\\n    when destroying those counters via a second client connection while\\n    changing those counters.\\n\\n    Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\\n    Fix:\u0026apos;, \u0026apos;Found by: Anonymous working with TrendAI Zero Day Initiative.\\n              (ZDI-CAN-30164)\u0026apos;, \u0026apos;This issue has been assigned CVE-2026-50261\u0026apos;, \u0026apos;* GLX ChangeDrawableAttributes Out-Of-Bounds Read/Write\\n\\n    A wrong size validation check in __glXDisp_ChangeDrawableAttributes()\\n    can read (or write) a client-contr(CVE-2026-50259)\n\nA use-after-free flaw was found in the X.Org X server and Xwayland in FreeCounter(). A client that sets up multiple SyncCounters and awaits on those triggers can trigger a use-after-free when destroying those counters via a second client connection. This may be used to crash the server, or for privilege escalation if the X server runs as root.(CVE-2026-50260)\n\nA use-after-free flaw was found in the X.Org X server and Xwayland in SyncChangeCounter(). A client that sets up multiple SyncCounters can trigger a use-after-free when destroying those counters via a second client connection while changing those counters. This may be used to crash the server, or for privilege escalation if the X server runs as root.(CVE-2026-50261)\n\nAn out-of-bounds read flaw was found in the X.Org X server and Xwayland in __glXDisp_ChangeDrawableAttributes(). A wrong size validation check can read a client-controlled number of bytes, exceeding the request buffer, leading to information disclosure. A write path also exists but requires byte-swapped clients which is disabled by default.(CVE-2026-50262)\n\n[\u0026apos;Hi all,\\n\\nCVEs have been issued now, please see inline below\\n\\nOn Tue, Jun 02, 2026 at 10:01:46AM +1000, Peter Hutterer wrote:\u0026apos;, \u0026quot;=======================================================================\\nX.Org Security Advisory: June 2, 2026 \\n\\nIssues in X.Org X server prior to 21.1.23 and Xwayland prior to 24.1.12\\n=======================================================================\\n\\nMultiple issues have been found in the X server and Xwayland implementations\\npublished by X.Org for which we are releasing security fixes for in\\nxorg-server-21.1.23 and xwayland-24.1.12.\\n\\nNote that CVEs have been requested for these issues but did not get assigned in\\ntime for this disclosure.\\n\\n* Font Alias Stack-based Buffer Overflow\\n\\n    A mismatch between the X server and the libXfont2 library\u0026apos;s maximum\\n    font name length can cause a stack buffer overflow during font alias\\n    resolution. The server allocates a 256 byte stack buffer but libXfont2\u0026apos;s\\n    alias target name length is 1024 bytes. A font alias name between 257\\n    and 1023 bytes causes the X server to copy that name into the undersized\\n    stack buffer without further checks.\\n\\n    Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\\n    Fix:\u0026quot;, \u0026apos;Found by: Anonymous working with TrendAI Zero Day Initiative.\\n              (ZDI-CAN-30136)\u0026apos;, \u0026apos;This issue has been assigned CVE-2026-50256\u0026apos;, \u0026apos;* XSYNC Use-After-Free in miSyncDestroyFence()\\n\\n    A client that sets up multiple fence triggers can trigger a\\n    use-after-free function pointer call. An attacker would connect to the\\n    X server to set up a fence and await that fence, then a second X\\n    connection destroys the fence, causing the use-after-free.\\n\\n    Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\\n    Fix:\u0026apos;, \u0026apos;Found by: Anonymous working with TrendAI Zero Day Initiative.\\n              (ZDI-CAN-30159)\u0026apos;, \u0026apos;This issue has been assigned CVE-2026-50257\u0026apos;, \u0026apos;* XKB Key Types Stack-based Buffer Overflow\\n\\n    The X server has multiple stack buffers that are sized\\n    XkbMaxShiftLevel * XkbNumKbdGroups but CheckKeyTypes() does not verify\\n    or clamp non-canonical key types to XkbMaxShiftLevel. A client can\\n    change key types to excessive shift levels and trigger three separate\\n    stack overflows.\\n\\n    This is caused by an incomplete fix of CVE-2025-26597.\\n\\n    Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\\n    Fix:\u0026apos;, \u0026apos;Found by: Anonymous working with TrendAI Zero Day Initiative.\\n              (ZDI-CAN-30160)\u0026apos;, \u0026apos;This issue has been assigned CVE-2026-50258\u0026apos;, \u0026apos;* XKB SetMap Request Stack-based Buffer Overflow\\n\\n    _XkbSetMapChecks() declares a fixed-size stack buffer mapWidths[256]\\n    indexed by key type index. The helper function CheckKeyTypes() writes\\n    to this buffer at a client-controlled offset, allowing a stack buffer\\n    overflow.\\n\\n    Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\\n    Fix:\u0026apos;, \u0026apos;Found by: Anonymous working with TrendAI Zero Day Initiative.\\n              (ZDI-CAN-30161)\u0026apos;, \u0026apos;This issue has been assigned CVE-2026-50259\u0026apos;, \u0026apos;* XSYNC Use-After-Free in FreeCounter()\\n\\n    A client that sets up multiple SyncCounters and awaits on those\\n    triggers can trigger a use-after-free when destroying those counters\\n    via a second client connection.\\n\\n    Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\\n    Fix:\u0026apos;, \u0026apos;Found by: Anonymous working with TrendAI Zero Day Initiative.\\n              (ZDI-CAN-30163)\u0026apos;, \u0026apos;This issue has been assigned CVE-2026-50260\u0026apos;, \u0026apos;* XSYNC Use-After-Free in SyncChangeCounter()\\n\\n    A client that sets up multiple SyncCounters can trigger a use-after-free\\n    when destroying those counters via a second client connection while\\n    changing those counters.\\n\\n    Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\\n    Fix:\u0026apos;, \u0026apos;Found by: Anonymous working with TrendAI Zero Day Initiative.\\n              (ZDI-CAN-30164)\u0026apos;, \u0026apos;This issue has been assigned CVE-2026-50261\u0026apos;, \u0026apos;* GLX ChangeDrawableAttributes Out-Of-Bounds Read/Write\\n\\n    A wrong size validation check in __glXDisp_ChangeDrawableAttributes()\\n    can read (or write) a client-contr(CVE-2026-50263)\n\nAn out-of-bounds write flaw was found in the X.Org X server and Xwayland in DRIGetBuffers/DRIGetBuffersWithFormat. A client that requests multiple DRI2BufferBackLeft attachments and one DRI2BufferFrontLeft can trigger an out-of-bounds heap write. This may be used to crash the server, or for privilege escalation if the X server runs as root.(CVE-2026-50264)",
  "id": "OESA-2026-2681",
  "modified": "2026-08-06T11:11:37Z",
  "published": "2026-06-12T11:11:37Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.openeuler.org/zh/security/security-bulletins/detail/?id=openEuler-SA-2026-2681"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-50256"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-50257"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-50258"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-50259"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-50260"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-50261"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-50262"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-50263"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-50264"
    }
  ],
  "schema_version": "1.7.2",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "xorg-x11-server security update",
  "upstream": [
    "CVE-2026-50256",
    "CVE-2026-50257",
    "CVE-2026-50258",
    "CVE-2026-50259",
    "CVE-2026-50260",
    "CVE-2026-50261",
    "CVE-2026-50262",
    "CVE-2026-50263",
    "CVE-2026-50264"
  ]
}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.


Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.