Vulnerability-Lookup

FKIE_CVE-2026-63803

Vulnerability from fkie_nvd - Published: 2026-07-19 12:16 - Updated: 2026-08-17 05:17

Severity

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

Summary

In the Linux kernel, the following vulnerability has been resolved: hdlc_ppp: sync per-proto timers before freeing hdlc state Each PPP control protocol (LCP/IPCP/IPV6CP) embedded in struct ppp registers a timer via timer_setup(). That struct ppp is the hdlc->state allocation, which detach_hdlc_protocol() frees with kfree() in both teardown paths: unregister_hdlc_device() and the re-attach inside attach_hdlc_protocol(). The ppp proto never registered a .detach callback, so detach_hdlc_protocol() performs no timer synchronization before the kfree(). The only cancel, timer_delete(&proto->timer) in ppp_cp_event(), is partial (it does not wait for a running callback) and only runs on the ->CLOSED transition; ppp_stop()/ppp_close() do not sync either. A ppp_timer callback already executing (blocked on ppp->lock) survives the kfree and then dereferences proto->state / ppp->lock in freed memory, leading to a use-after-free. Fix this by adding a .detach helper that calls timer_shutdown_sync() on every per-proto timer. detach_hdlc_protocol() invokes proto->detach(dev) before kfree(hdlc->state), so timer_shutdown_sync() now runs on both free paths. timer_shutdown_sync() is used instead of timer_delete_sync() because the keepalive path re-arms the timer through add_timer()/mod_timer() and shutdown blocks any re-activation during teardown. Initialize the per-protocol timers in ppp_ioctl() when the protocol is attached, and remove the now-redundant timer_setup() from ppp_start(), so that the timers are initialized exactly once at attach time and ppp_timer_release() never operates on uninitialized timer_list structures. attach_hdlc_protocol() uses kmalloc() (not kzalloc), so struct ppp's protos[i].timer is uninitialized garbage until the first timer_setup(); without this init-at-attach, attaching the PPP protocol without ever bringing the device up would leave timer_shutdown_sync() operating on uninitialized memory in .detach. Moving the init out of ppp_start() (which only runs on NETDEV_UP) into the attach path makes the initialization unconditional and avoids initializing the same timer_list twice. This bug was found by static analysis.

References

URL	Tags
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/508a0139d3bf60f6a03d2fbfb63a89a9463d983a	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/5a84398101bf9f11e84b176343e4e3ba83e668c0	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/8308122bc9c065b1f376e081ed300129a2ac9545	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/86d80a231bde4cfb64bfbfbfffd83056fc93628f	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/a594debfd4e7ec39413647458907f689ef57fd2f	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/c64dbef1c0fbd36f9530aa75112acdf6a6d3cfd8	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/c78a4e41ab5ead6193ad8a2dd92e8906bae659fa	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/ce8f9ddca0c9f217342a8b49efd309aa35b81a36	Patch

Impacted products

Vendor	Product	Version
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	2.6.12
linux	linux_kernel	2.6.12
linux	linux_kernel	2.6.12
linux	linux_kernel	2.6.12
linux	linux_kernel	2.6.12

JSON

To clipboard

{
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          "product": "Linux",
          "programFiles": [
            "drivers/net/wan/hdlc_ppp.c"
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              "status": "unaffected",
              "version": "5.15.211",
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              "status": "unaffected",
              "version": "6.1.177",
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  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nhdlc_ppp: sync per-proto timers before freeing hdlc state\n\nEach PPP control protocol (LCP/IPCP/IPV6CP) embedded in struct ppp\nregisters a timer via timer_setup(). That struct ppp is the\nhdlc-\u003estate allocation, which detach_hdlc_protocol() frees with kfree()\nin both teardown paths: unregister_hdlc_device() and the re-attach inside\nattach_hdlc_protocol().\n\nThe ppp proto never registered a .detach callback, so\ndetach_hdlc_protocol() performs no timer synchronization before the\nkfree(). The only cancel, timer_delete(\u0026proto-\u003etimer) in ppp_cp_event(),\nis partial (it does not wait for a running callback) and only runs on the\n-\u003eCLOSED transition; ppp_stop()/ppp_close() do not sync either. A\nppp_timer callback already executing (blocked on ppp-\u003elock) survives the\nkfree and then dereferences proto-\u003estate / ppp-\u003elock in freed memory,\nleading to a use-after-free.\n\nFix this by adding a .detach helper that calls timer_shutdown_sync() on\nevery per-proto timer. detach_hdlc_protocol() invokes proto-\u003edetach(dev)\nbefore kfree(hdlc-\u003estate), so timer_shutdown_sync()\nnow runs on both free paths.\ntimer_shutdown_sync() is used instead of timer_delete_sync() because the\nkeepalive path re-arms the timer through add_timer()/mod_timer() and\nshutdown blocks any re-activation during teardown.\n\nInitialize the per-protocol timers in ppp_ioctl() when the protocol is\nattached, and remove the now-redundant timer_setup() from ppp_start(), so\nthat the timers are initialized exactly once at attach time and\nppp_timer_release() never operates on uninitialized timer_list\nstructures. attach_hdlc_protocol() uses kmalloc() (not kzalloc), so\nstruct ppp\u0027s protos[i].timer is uninitialized garbage until the first\ntimer_setup(); without this init-at-attach, attaching the PPP protocol\nwithout ever bringing the device up would leave timer_shutdown_sync()\noperating on uninitialized memory in .detach. Moving the init out of\nppp_start() (which only runs on NETDEV_UP) into the attach path makes the\ninitialization unconditional and avoids initializing the same timer_list\ntwice.\n\nThis bug was found by static analysis."
    }
  ],
  "id": "CVE-2026-63803",
  "lastModified": "2026-08-17T05:17:16.867",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 7.8,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.9,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-07-19T12:16:52.980",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/508a0139d3bf60f6a03d2fbfb63a89a9463d983a"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/5a84398101bf9f11e84b176343e4e3ba83e668c0"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/8308122bc9c065b1f376e081ed300129a2ac9545"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/86d80a231bde4cfb64bfbfbfffd83056fc93628f"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/a594debfd4e7ec39413647458907f689ef57fd2f"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/c64dbef1c0fbd36f9530aa75112acdf6a6d3cfd8"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/c78a4e41ab5ead6193ad8a2dd92e8906bae659fa"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/ce8f9ddca0c9f217342a8b49efd309aa35b81a36"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-416"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}

CVE-2026-63803 (GCVE-0-2026-63803)

Vulnerability from cvelistv5 – Published: 2026-07-19 12:02 – Updated: 2026-08-17 04:51

Title

hdlc_ppp: sync per-proto timers before freeing hdlc state

Summary

Severity

7.8 (High)


                        
                          CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Assigner

Linux mitre root

References

8 references

URL	Tags
https://git.kernel.org/stable/c/86d80a231bde4cfb6…
https://git.kernel.org/stable/c/8308122bc9c065b1f…
https://git.kernel.org/stable/c/ce8f9ddca0c9f2173…
https://git.kernel.org/stable/c/508a0139d3bf60f6a…
https://git.kernel.org/stable/c/c64dbef1c0fbd36f9…
https://git.kernel.org/stable/c/5a84398101bf9f11e…
https://git.kernel.org/stable/c/a594debfd4e7ec394…
https://git.kernel.org/stable/c/c78a4e41ab5ead619…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 86d80a231bde4cfb64bfbfbfffd83056fc93628f (git) Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 8308122bc9c065b1f376e081ed300129a2ac9545 (git) Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < ce8f9ddca0c9f217342a8b49efd309aa35b81a36 (git) Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 508a0139d3bf60f6a03d2fbfb63a89a9463d983a (git) Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < c64dbef1c0fbd36f9530aa75112acdf6a6d3cfd8 (git) Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 5a84398101bf9f11e84b176343e4e3ba83e668c0 (git) Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < a594debfd4e7ec39413647458907f689ef57fd2f (git) Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < c78a4e41ab5ead6193ad8a2dd92e8906bae659fa (git)
Linux	Linux	Affected: 2.6.12 Unaffected: 0 , < 2.6.12 (semver) Unaffected: 5.10.261 , ≤ 5.10.* (semver) Unaffected: 5.15.211 , ≤ 5.15.* (semver) Unaffected: 6.1.177 , ≤ 6.1.* (semver) Unaffected: 6.6.144 , ≤ 6.6.* (semver) Unaffected: 6.12.95 , ≤ 6.12.* (semver) Unaffected: 6.18.38 , ≤ 6.18.* (semver) Unaffected: 7.1.3 , ≤ 7.1.* (semver) Unaffected: 7.2 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/net/wan/hdlc_ppp.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "86d80a231bde4cfb64bfbfbfffd83056fc93628f",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
            {
              "lessThan": "8308122bc9c065b1f376e081ed300129a2ac9545",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
            {
              "lessThan": "ce8f9ddca0c9f217342a8b49efd309aa35b81a36",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
            {
              "lessThan": "508a0139d3bf60f6a03d2fbfb63a89a9463d983a",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
            {
              "lessThan": "c64dbef1c0fbd36f9530aa75112acdf6a6d3cfd8",
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              "versionType": "git"
            },
            {
              "lessThan": "5a84398101bf9f11e84b176343e4e3ba83e668c0",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
            {
              "lessThan": "a594debfd4e7ec39413647458907f689ef57fd2f",
              "status": "affected",
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              "versionType": "git"
            },
            {
              "lessThan": "c78a4e41ab5ead6193ad8a2dd92e8906bae659fa",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/net/wan/hdlc_ppp.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "2.6.12"
            },
            {
              "lessThan": "2.6.12",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.261",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.211",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.177",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.144",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.95",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.38",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.3",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.10.261",
                  "versionStartIncluding": "2.6.12",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.15.211",
                  "versionStartIncluding": "2.6.12",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.1.177",
                  "versionStartIncluding": "2.6.12",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.144",
                  "versionStartIncluding": "2.6.12",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.95",
                  "versionStartIncluding": "2.6.12",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.38",
                  "versionStartIncluding": "2.6.12",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1.3",
                  "versionStartIncluding": "2.6.12",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2",
                  "versionStartIncluding": "2.6.12",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nhdlc_ppp: sync per-proto timers before freeing hdlc state\n\nEach PPP control protocol (LCP/IPCP/IPV6CP) embedded in struct ppp\nregisters a timer via timer_setup(). That struct ppp is the\nhdlc-\u003estate allocation, which detach_hdlc_protocol() frees with kfree()\nin both teardown paths: unregister_hdlc_device() and the re-attach inside\nattach_hdlc_protocol().\n\nThe ppp proto never registered a .detach callback, so\ndetach_hdlc_protocol() performs no timer synchronization before the\nkfree(). The only cancel, timer_delete(\u0026proto-\u003etimer) in ppp_cp_event(),\nis partial (it does not wait for a running callback) and only runs on the\n-\u003eCLOSED transition; ppp_stop()/ppp_close() do not sync either. A\nppp_timer callback already executing (blocked on ppp-\u003elock) survives the\nkfree and then dereferences proto-\u003estate / ppp-\u003elock in freed memory,\nleading to a use-after-free.\n\nFix this by adding a .detach helper that calls timer_shutdown_sync() on\nevery per-proto timer. detach_hdlc_protocol() invokes proto-\u003edetach(dev)\nbefore kfree(hdlc-\u003estate), so timer_shutdown_sync()\nnow runs on both free paths.\ntimer_shutdown_sync() is used instead of timer_delete_sync() because the\nkeepalive path re-arms the timer through add_timer()/mod_timer() and\nshutdown blocks any re-activation during teardown.\n\nInitialize the per-protocol timers in ppp_ioctl() when the protocol is\nattached, and remove the now-redundant timer_setup() from ppp_start(), so\nthat the timers are initialized exactly once at attach time and\nppp_timer_release() never operates on uninitialized timer_list\nstructures. attach_hdlc_protocol() uses kmalloc() (not kzalloc), so\nstruct ppp\u0027s protos[i].timer is uninitialized garbage until the first\ntimer_setup(); without this init-at-attach, attaching the PPP protocol\nwithout ever bringing the device up would leave timer_shutdown_sync()\noperating on uninitialized memory in .detach. Moving the init out of\nppp_start() (which only runs on NETDEV_UP) into the attach path makes the\ninitialization unconditional and avoids initializing the same timer_list\ntwice.\n\nThis bug was found by static analysis."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.8,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - The UAF occurs in detach_hdlc_protocol() during protocol teardown via SIOCWANDEV ioctl or driver unregister, not during packet receive. Remote PPP peers can influence timers but cannot reach the kfree() path without local CAP_NET_ADMIN configuration actions.\nAC:L - An attacker with CAP_NET_ADMIN can reliably trigger the bug by bringing a PPP HDLC interface up (arming timers via ppp_start/LCP), then tearing down or re-attaching the protocol while timers are pending or a ppp_timer callback is blocked on ppp-\u003elock, controlling both sides of the race.\nPR:L - Exploitation requires CAP_NET_ADMIN to attach/detach the PPP protocol via SIOCWANDEV (ppp_ioctl checks capable(CAP_NET_ADMIN)), which is reachable by unprivileged users who create user namespaces with CAP_NET_ADMIN per kernel CVSS guidance.\nUI:N - No victim interaction is required once the attacker has network administration capability on a system with an HDLC WAN device; exploitation is fully attacker-driven through ioctl and interface up/down operations.\nS:U - The use-after-free corrupts kernel heap memory within the same kernel security boundary, enabling local privilege escalation rather than crossing a VM, container, or IOMMU security boundary.\nC:H - Use-after-free of struct ppp and its embedded spinlock_t allows dereferencing attacker-influenced freed heap memory, which can be leveraged for arbitrary kernel memory read via heap grooming and controlled reuse of the freed slab object.\nI:H - The UAF on struct ppp and ppp-\u003elock provides a standard kernel heap corruption primitive that can be developed into arbitrary write and local privilege escalation through control of reallocated object contents and spinlock corruption.\nA:H - The freed-memory dereference in ppp_timer() causes kernel oops or panic during protocol teardown, and repeated triggering during interface reconfiguration can cause sustained denial of service on WAN router systems."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-17T04:51:08.890Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/86d80a231bde4cfb64bfbfbfffd83056fc93628f"
        },
        {
          "url": "https://git.kernel.org/stable/c/8308122bc9c065b1f376e081ed300129a2ac9545"
        },
        {
          "url": "https://git.kernel.org/stable/c/ce8f9ddca0c9f217342a8b49efd309aa35b81a36"
        },
        {
          "url": "https://git.kernel.org/stable/c/508a0139d3bf60f6a03d2fbfb63a89a9463d983a"
        },
        {
          "url": "https://git.kernel.org/stable/c/c64dbef1c0fbd36f9530aa75112acdf6a6d3cfd8"
        },
        {
          "url": "https://git.kernel.org/stable/c/5a84398101bf9f11e84b176343e4e3ba83e668c0"
        },
        {
          "url": "https://git.kernel.org/stable/c/a594debfd4e7ec39413647458907f689ef57fd2f"
        },
        {
          "url": "https://git.kernel.org/stable/c/c78a4e41ab5ead6193ad8a2dd92e8906bae659fa"
        }
      ],
      "title": "hdlc_ppp: sync per-proto timers before freeing hdlc state",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-63803",
    "datePublished": "2026-07-19T12:02:08.574Z",
    "dateReserved": "2026-07-19T07:54:57.013Z",
    "dateUpdated": "2026-08-17T04:51:08.890Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

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.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.

Action not permitted

FKIE_CVE-2026-63803

CVE-2026-63803 (GCVE-0-2026-63803)

Tags

Sightings

Nomenclature