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5.0 Medium

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

Description

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.

CVSS 3.1 detail

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

Exploitable with local access to the machine, with an ordinary account and if a user takes an action; an attacker can seriously compromise confidentiality, integrity or availability.

Attack vector
Local
Attack complexity
High
Privileges required
Low
Interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
Low
Availability
None

Affected products and versions

Product Affected versions Fixed in
Red Hat Enterprise Linux 10 Versions not published
Red Hat Enterprise Linux 6 Versions not published
Red Hat Enterprise Linux 7 Versions not published
Red Hat Enterprise Linux 8 Versions not published
Red Hat Enterprise Linux 9 Versions not published
Red Hat Hardened Images 10.3 earliest → < 10.3p1-6.hum1 10.3p1-6.hum1
Red Hat OpenShift Container Platform 4 Versions not published
Red Hat Update Infrastructure 5 1787241260 earliest → < 1787241260 1787241260
Red Hat Enterprise Linux 10.0 Extended Update Support Versions not published
Show the 9 other branches
Product Affected versions Fixed in
Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions Versions not published
Red Hat Enterprise Linux 9.6 Extended Update Support Versions not published
Red Hat OpenShift AI 3.4 1791885505 earliest → < 1791885505 1791885505
Red Hat OpenShift AI 3.0 1793042072 earliest → < 1793042072 1793042072
Red Hat OpenShift AI 3.2 1791818512 earliest → < 1791818512 1791818512
Red Hat OpenShift AI 3.3 1791818877 earliest → < 1791818877 1791818877
Red Hat OpenShift AI 3.5 1791819104 earliest → < 1791819104 1791819104
Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions Versions not published
Red Hat OpenShift Container Platform 5 Versions not published

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