# CVE-2026-55655: Openssh: local mitm of x11 forwarding via abstract unix socket pre-binding in red hat enterprise linux openssh client versions

Status: published. Published: 2026-06-23. Updated: 2026-11-05.

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.

## Remediation

- workaround: To mitigate this issue, disable X11 forwarding on OpenSSH clients when it is not required. This can be achieved by avoiding the use of `-X` or `-Y` options when invoking `ssh`, or by setting `ForwardX11 no` in the SSH client configuration file (`~/.ssh/config` or `/etc/ssh/ssh_config`). Disabling X11 forwarding will prevent the client from attempting to establish X11 connections, thereby removing the attack vector. (source: CNA: redhat)

## Affected products and versions

- Red Hat / Red Hat Enterprise Linux 10 (openssh): ≥ 0:9.9p1-25.el10_2; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 10.0 Extended Update Support (openssh): ≥ 0:9.9p1-7.el10_0.5; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 8 (openssh): ≥ 0:8.0p1-30.el8_10; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 9 (openssh): ≥ 0:9.9p1-9.el9_8; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions (openssh): ≥ 0:8.7p1-30.el9_2.13; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions (openssh): ≥ 0:8.7p1-38.el9_4.10; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 9.6 Extended Update Support (openssh): ≥ 0:8.7p1-45.el9_6.5; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Hardened Images (openssh-main): ≥ 10.3p1-6.hum1; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat OpenShift AI 3.0 (rhai/base-image-cuda-rhel9): ≥ 1791818590; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat OpenShift AI 3.0 (rhai/base-image-cpu-rhel9): ≥ 1791818589; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat OpenShift AI 3.0 (rhai/base-image-spyre-rhel9): ≥ 1791818505; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat OpenShift AI 3.0 (rhai/base-image-tpu-rhel9): ≥ 1791818496; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat OpenShift AI 3.0 (rhai/base-image-rocm-rhel9): ≥ 1791818502; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat OpenShift AI 3.0 (rhai/base-image-cpu-rhel9): ≥ 1793042072; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat OpenShift AI 3.2 (rhai/base-image-spyre-rhel9): ≥ 1791818602; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat OpenShift AI 3.2 (rhai/base-image-cpu-rhel9): ≥ 1791818598; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat OpenShift AI 3.2 (rhai/base-image-tpu-rhel9): ≥ 1791818512; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat OpenShift AI 3.2 (rhai/base-image-cuda-rhel9): ≥ 1791818587; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat OpenShift AI 3.2 (rhai/base-image-rocm-rhel9): ≥ 1791818778; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat OpenShift AI 3.2 (rhai/base-image-rocm-rhel9): ≥ 1791818512; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat OpenShift AI 3.3 (rhai/base-image-tpu-rhel9): ≥ 1791818782; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat OpenShift AI 3.3 (rhai/base-image-rocm-6.4-rhel9): ≥ 1791818782; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat OpenShift AI 3.3 (rhai/base-image-cuda-12.9-rhel9): ≥ 1791818627; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat OpenShift AI 3.3 (rhai/base-image-rocm-7.0-rhel9): ≥ 1791818790; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat OpenShift AI 3.3 (rhai/base-image-cpu-rhel9): ≥ 1791818874; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat OpenShift AI 3.3 (rhai/base-image-neuron-rhel9): ≥ 1791818792; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat OpenShift AI 3.3 (rhai/base-image-cuda-13.0-rhel9): ≥ 1791818662; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat OpenShift AI 3.3 (rhai/base-image-spyre-rhel9): ≥ 1791818877; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat OpenShift AI 3.4 (rhai/base-image-neuron-rhel9): ≥ 1791883722; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat OpenShift AI 3.4 (rhai/base-image-cuda-12.9-rhel9): ≥ 1791881612; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat OpenShift AI 3.4 (rhai/base-image-cpu-rhel9): ≥ 1791885618; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat OpenShift AI 3.4 (rhai/base-image-rocm-6.4-rhel9): ≥ 1791881487; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat OpenShift AI 3.4 (rhai/base-image-spyre-rhel9): ≥ 1791881732; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat OpenShift AI 3.4 (rhai/base-image-rocm-7.1-rhel9): ≥ 1791883315; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat OpenShift AI 3.4 (rhai/base-image-gaudi-rhel9): ≥ 1791881486; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat OpenShift AI 3.4 (rhai/base-image-tpu-rhel9): ≥ 1791881769; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat OpenShift AI 3.4 (rhai/base-image-cuda-13.0-rhel9): ≥ 1791885505; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat OpenShift AI 3.5 (rhai/base-image-spyre-rhel9): ≥ 1791819252; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat OpenShift AI 3.5 (rhai/base-image-gaudi-rhel9): ≥ 1791818749; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat OpenShift AI 3.5 (rhai/base-image-cpu-rhel9): ≥ 1791819206; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat OpenShift AI 3.5 (rhai/base-image-neuron-rhel9): ≥ 1791818979; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat OpenShift AI 3.5 (rhai/base-image-rocm-7.14-rhel9): ≥ 1791819123; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat OpenShift AI 3.5 (rhai/base-image-tpu-rhel9): ≥ 1791818901; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat OpenShift AI 3.5 (rhai/base-image-rubin-rhel9): ≥ 1791820333; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat OpenShift AI 3.5 (rhai/base-image-cuda-13.0-rhel9): ≥ 1791819495; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat OpenShift AI 3.5 (rhai/base-image-cuda-12.9-rhel9): ≥ 1791819104; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Update Infrastructure 5 (rhui5/installer-rhel9): ≥ 1786435483; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Update Infrastructure 5 (rhui5/rhua-rhel9): ≥ 1786533529; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Update Infrastructure 5 (rhui5/installer-tp-rhel9): ≥ 1787135742; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Update Infrastructure 5 (rhui5/rhua-tp-rhel9): ≥ 1787241260; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 6 (openssh): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 7 (openssh): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat OpenShift Container Platform 4 (openshift/ose-rhel-coreos-8): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat OpenShift Container Platform 4 (openshift/ose-rhel-coreos-9): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat OpenShift Container Platform 5 (openshift/ose-rhel-coreos-9): Version range not reported. Source: CNA: redhat

## Severity and prioritization

- CVSS 3.1: 5 (medium); CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:H/I:L/A:N; source: CNA: redhat

- CISA KEV: No listing in collected sources

- EPSS: 0.12% as of 2026-11-05; percentile 2.13%

- SSVC: exploitation none; automatable no; technical impact partial; source ADP: CISA-ADP

- Weaknesses: CWE-923

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://access.redhat.com/errata/RHSA-2026:36759 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:47755 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:47756 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:47757 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:54387 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:58981 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:76748 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:76993 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:80513 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:82749 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:82750 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:82751 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:82752 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:82753 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:82754 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:82755 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:82756 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:82757 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:82758 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:82759 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:82761 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:82762 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:82763 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:82897 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:82898 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:82899 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:82900 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:82901 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:82902 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:82903 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:82904 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:82907 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:82908 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:82909 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:82910 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:82912 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:82913 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:82914 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:82915 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:82916 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:82917 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:82918 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:82920 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:82921 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:82922 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:82923 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:89739 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:91232 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/security/cve/CVE-2026-55655 (CNA: redhat; vdb-entry, x_refsource_REDHAT)

- https://bugzilla.redhat.com/show_bug.cgi?id=2462250 (CNA: redhat; issue-tracking, x_refsource_REDHAT)

## Provenance

- CNA: redhat: https://www.cve.org/CVERecord?id=CVE-2026-55655; retrieved 2026-11-05; source updated 2026-11-05

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-55655; retrieved 2026-11-05; source updated Not reported

Revision: 168b9b03e38f9e4b8e492d64136f7e8c3252200ef80bbd3061c0ff921ea936f6

Canonical: https://y2.dev/cve/CVE-2026-55655

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