CVE-2026-55655

medium

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.

References

https://access.redhat.com/errata/RHSA-2026:89739

https://access.redhat.com/errata/RHSA-2026:82923

https://access.redhat.com/errata/RHSA-2026:82922

https://access.redhat.com/errata/RHSA-2026:82921

https://access.redhat.com/errata/RHSA-2026:82920

https://access.redhat.com/errata/RHSA-2026:82918

https://access.redhat.com/errata/RHSA-2026:82917

https://access.redhat.com/errata/RHSA-2026:82916

https://access.redhat.com/errata/RHSA-2026:82915

https://access.redhat.com/errata/RHSA-2026:82914

https://access.redhat.com/errata/RHSA-2026:82913

https://access.redhat.com/errata/RHSA-2026:82912

https://access.redhat.com/errata/RHSA-2026:82910

https://access.redhat.com/errata/RHSA-2026:82909

https://access.redhat.com/errata/RHSA-2026:82908

https://access.redhat.com/errata/RHSA-2026:82907

https://access.redhat.com/errata/RHSA-2026:82904

https://access.redhat.com/errata/RHSA-2026:82903

https://access.redhat.com/errata/RHSA-2026:82902

https://access.redhat.com/errata/RHSA-2026:82901

https://access.redhat.com/errata/RHSA-2026:82900

https://access.redhat.com/errata/RHSA-2026:82899

https://access.redhat.com/errata/RHSA-2026:82898

https://access.redhat.com/errata/RHSA-2026:82897

https://access.redhat.com/errata/RHSA-2026:82763

https://access.redhat.com/errata/RHSA-2026:82762

https://access.redhat.com/errata/RHSA-2026:82761

https://access.redhat.com/errata/RHSA-2026:82759

https://access.redhat.com/errata/RHSA-2026:82758

https://access.redhat.com/errata/RHSA-2026:82757

https://access.redhat.com/errata/RHSA-2026:82756

https://access.redhat.com/errata/RHSA-2026:82755

https://access.redhat.com/errata/RHSA-2026:82754

https://access.redhat.com/errata/RHSA-2026:82753

https://access.redhat.com/errata/RHSA-2026:82752

https://access.redhat.com/errata/RHSA-2026:82751

https://access.redhat.com/errata/RHSA-2026:82750

https://access.redhat.com/errata/RHSA-2026:82749

https://access.redhat.com/errata/RHSA-2026:80513

https://access.redhat.com/errata/RHSA-2026:76993

https://access.redhat.com/errata/RHSA-2026:76748

https://access.redhat.com/errata/RHSA-2026:58981

https://access.redhat.com/errata/RHSA-2026:54387

https://access.redhat.com/errata/RHSA-2026:47757

https://access.redhat.com/errata/RHSA-2026:47756

https://access.redhat.com/errata/RHSA-2026:47755

https://access.redhat.com/errata/RHSA-2026:36759

Details

Source: Mitre, NVD

Published: 2026-06-23

Updated: 2026-10-26

Risk Information

CVSS v2

Base Score: 5.6

Vector: CVSS2#AV:L/AC:L/Au:N/C:C/I:P/A:N

Severity: Medium

CVSS v3

Base Score: 6.1

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

Severity: Medium

EPSS

EPSS: 0.00124