Vulnerability-Lookup

alsa-2026:47755

Vulnerability from osv_almalinux

Published

2026-07-29 00:00

Modified

2026-07-30 13:16

Summary

Moderate: openssh security update

Details

OpenSSH is an SSH protocol implementation supported by a number of Linux, UNIX, and similar operating systems. It includes the core files necessary for both the OpenSSH client and server.

Security Fix(es):

openssh: Local MITM of X11 forwarding via abstract UNIX socket pre-binding in AlmaLinux OpenSSH client versions (CVE-2026-55655)
openssh: Double free in AlmaLinux versions of OpenSSH DH-GEX client path during FIPS known-group validation leads to client-side denial of service (CVE-2026-55653)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

References

URL

Type

	https://access.redhat.com/errata/RHSA-2026:47755	ADVISORY
	https://access.redhat.com/security/cve/CVE-2026-55653	REPORT
	https://access.redhat.com/security/cve/CVE-2026-55655	REPORT
	https://bugzilla.redhat.com/2462250	REPORT
	https://bugzilla.redhat.com/2462351	REPORT
	https://errata.almalinux.org/8/ALSA-2026-47755.html	ADVISORY

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "AlmaLinux:8",
        "name": "openssh"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "8.0p1-30.el8_10"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "AlmaLinux:8",
        "name": "openssh-askpass"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "8.0p1-30.el8_10"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "AlmaLinux:8",
        "name": "openssh-cavs"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "8.0p1-30.el8_10"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "AlmaLinux:8",
        "name": "openssh-clients"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "8.0p1-30.el8_10"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "AlmaLinux:8",
        "name": "openssh-keycat"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "8.0p1-30.el8_10"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "AlmaLinux:8",
        "name": "openssh-ldap"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "8.0p1-30.el8_10"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "AlmaLinux:8",
        "name": "openssh-server"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "8.0p1-30.el8_10"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "AlmaLinux:8",
        "name": "pam_ssh_agent_auth"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.10.3-7.30.el8_10"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "details": "OpenSSH is an SSH protocol implementation supported by a number of Linux, UNIX, and similar operating systems. It includes the core files necessary for both the OpenSSH client and server.  \n\nSecurity Fix(es):  \n\n  * openssh: Local MITM of X11 forwarding via abstract UNIX socket pre-binding in AlmaLinux OpenSSH client versions (CVE-2026-55655)\n  * openssh: Double free in AlmaLinux versions of OpenSSH DH-GEX client path during FIPS known-group validation leads to client-side denial of service (CVE-2026-55653)\n\n\nFor more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.\n",
  "id": "ALSA-2026:47755",
  "modified": "2026-07-30T13:16:14Z",
  "published": "2026-07-29T00:00:00Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://access.redhat.com/errata/RHSA-2026:47755"
    },
    {
      "type": "REPORT",
      "url": "https://access.redhat.com/security/cve/CVE-2026-55653"
    },
    {
      "type": "REPORT",
      "url": "https://access.redhat.com/security/cve/CVE-2026-55655"
    },
    {
      "type": "REPORT",
      "url": "https://bugzilla.redhat.com/2462250"
    },
    {
      "type": "REPORT",
      "url": "https://bugzilla.redhat.com/2462351"
    },
    {
      "type": "ADVISORY",
      "url": "https://errata.almalinux.org/8/ALSA-2026-47755.html"
    }
  ],
  "related": [
    "CVE-2026-55655",
    "CVE-2026-55653"
  ],
  "summary": "Moderate: openssh security update"
}

CVE-2026-55653 (GCVE-0-2026-55653)

Vulnerability from cvelistv5 – Published: 2026-06-23 03:36 – Updated: 2026-07-30 08:22

Title

Openssh: double free in red hat enterprise linux versions of openssh dh-gex client path during fips known-group validation leads to client-side denial of service

Summary

A flaw was found in OpenSSH. A malicious SSH server can exploit a double free vulnerability in the Diffie-Hellman Group Exchange (DH-GEX) client path. This occurs during FIPS (Federal Information Processing Standards) mode known-group validation when the client processes attacker-controlled DH-GEX group parameters. Successful exploitation leads to client-side process termination, resulting in a Denial of Service (DoS).

Severity

4.3 (Medium)


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

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator (v2.0.3)

CWE

CWE-415 - Double Free

Assigner

redhat

References

6 references

URL	Tags
https://access.redhat.com/errata/RHSA-2026:36759	vendor-advisoryx_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:47755	vendor-advisoryx_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:47756	vendor-advisoryx_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:47757	vendor-advisoryx_refsource_REDHAT
https://access.redhat.com/security/cve/CVE-2026-55653	vdb-entryx_refsource_REDHAT
https://bugzilla.redhat.com/show_bug.cgi?id=2462351	issue-trackingx_refsource_REDHAT

Impacted products

7 products

Vendor	Product	Version
Red Hat	Red Hat Enterprise Linux 10	Unaffected: 0:9.9p1-25.el10_2 , < * (rpm) cpe:/o:redhat:enterprise_linux:10.2
Red Hat	Red Hat Enterprise Linux 8	Unaffected: 0:8.0p1-30.el8_10 , < * (rpm) cpe:/a:redhat:enterprise_linux:8::appstream cpe:/o:redhat:enterprise_linux:8::baseos
Red Hat	Red Hat Enterprise Linux 9	Unaffected: 0:9.9p1-9.el9_8 , < * (rpm) cpe:/a:redhat:enterprise_linux:9::appstream cpe:/o:redhat:enterprise_linux:9::baseos
Red Hat	Red Hat Hardened Images	Unaffected: 10.3p1-6.hum1 , < * (rpm) cpe:/a:redhat:hummingbird:1
Red Hat	Red Hat Enterprise Linux 6	cpe:/o:redhat:enterprise_linux:6
Red Hat	Red Hat Enterprise Linux 7	cpe:/o:redhat:enterprise_linux:7
Red Hat	Red Hat OpenShift Container Platform 4	cpe:/a:redhat:openshift:4

Date Public

2026-06-22 23:17

Show details on NVD website

JSON

To clipboard

{
  "containers": {
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      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-55653",
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        {
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "cpes": [
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        }
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    "assignerShortName": "redhat",
    "cveId": "CVE-2026-55653",
    "datePublished": "2026-06-23T03:36:22.741Z",
    "dateReserved": "2026-06-16T23:55:05.737Z",
    "dateUpdated": "2026-07-30T08:22:19.409Z",
    "state": "PUBLISHED"
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  "dataVersion": "5.2"
}

CVE-2026-55655 (GCVE-0-2026-55655)

Vulnerability from cvelistv5 – Published: 2026-06-23 03:36 – Updated: 2026-07-30 08:22

Title

Openssh: local mitm of x11 forwarding via abstract unix socket pre-binding in red hat enterprise linux openssh client versions

Summary

A flaw was found in OpenSSH. A local unprivileged attacker on a Linux client host can hijack client-side X11 forwarding connections. This is possible by pre-binding the preferred abstract X socket name when X11 forwarding is enabled and a local UNIX-domain X socket is used. A successful attack can compromise the confidentiality of forwarded X11 traffic, including sensitive window contents and input, and may allow some manipulation of the forwarded session.

Severity

5 (Medium)


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

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator (v2.0.3)

CWE

CWE-923 - Improper Restriction of Communication Channel to Intended Endpoints

Assigner

redhat

References

6 references

URL	Tags
https://access.redhat.com/errata/RHSA-2026:36759	vendor-advisoryx_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:47755	vendor-advisoryx_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:47756	vendor-advisoryx_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:47757	vendor-advisoryx_refsource_REDHAT
https://access.redhat.com/security/cve/CVE-2026-55655	vdb-entryx_refsource_REDHAT
https://bugzilla.redhat.com/show_bug.cgi?id=2462250	issue-trackingx_refsource_REDHAT

Impacted products

7 products

Vendor	Product	Version
Red Hat	Red Hat Enterprise Linux 10	Unaffected: 0:9.9p1-25.el10_2 , < * (rpm) cpe:/o:redhat:enterprise_linux:10.2
Red Hat	Red Hat Enterprise Linux 8	Unaffected: 0:8.0p1-30.el8_10 , < * (rpm) cpe:/a:redhat:enterprise_linux:8::appstream cpe:/o:redhat:enterprise_linux:8::baseos
Red Hat	Red Hat Enterprise Linux 9	Unaffected: 0:9.9p1-9.el9_8 , < * (rpm) cpe:/a:redhat:enterprise_linux:9::appstream cpe:/o:redhat:enterprise_linux:9::baseos
Red Hat	Red Hat Hardened Images	Unaffected: 10.3p1-6.hum1 , < * (rpm) cpe:/a:redhat:hummingbird:1
Red Hat	Red Hat Enterprise Linux 6	cpe:/o:redhat:enterprise_linux:6
Red Hat	Red Hat Enterprise Linux 7	cpe:/o:redhat:enterprise_linux:7
Red Hat	Red Hat OpenShift Container Platform 4	cpe:/a:redhat:openshift:4

Date Public

2026-06-22 23:22

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-55655",
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                    "Technical Impact": "partial"
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                "role": "CISA Coordinator",
                "timestamp": "2026-06-23T12:21:42.502865Z",
                "version": "2.0.3"
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          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
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      }
    ],
    "cna": {
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          "cpes": [
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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.

Action not permitted

alsa-2026:47755

Vulnerability from osv_almalinux

CVE-2026-55653 (GCVE-0-2026-55653)

CVE-2026-55655 (GCVE-0-2026-55655)

Tags

Sightings

Nomenclature