Improper Restriction of Communication Channel to Intended Endpoints Affecting openssh-keysign package, versions <0:9.9p1-25.el10_2.alma.1


Severity

Recommended
high

Based on AlmaLinux security rating.

Threat Intelligence

EPSS
0.14% (3rd percentile)

Do your applications use this vulnerable package?

In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.

Test your applications
  • Snyk IDSNYK-ALMALINUX10-OPENSSHKEYSIGN-18477409
  • published31 Jul 2026
  • disclosed29 Jul 2026

Introduced: 29 Jul 2026

CVE-2026-55655  (opens in a new tab)
CWE-923  (opens in a new tab)

How to fix?

Upgrade AlmaLinux:10 openssh-keysign to version 0:9.9p1-25.el10_2.alma.1 or higher.
This issue was patched in ALSA-2026:47757.

NVD Description

Note: Versions mentioned in the description apply only to the upstream openssh-keysign package and not the openssh-keysign package as distributed by AlmaLinux. See How to fix? for AlmaLinux:10 relevant fixed versions and status.

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

CVSS Base Scores

version 3.1