Improper Restriction of Communication Channel to Intended Endpoints Affecting openssh package, versions <1:10.4p1-1+e2


Severity

Recommended
0.0
medium
0
10

Snyk's Security Team recommends NVD's CVSS assessment. Learn more

Threat Intelligence

EPSS
0.13% (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-ECHOLATEST-OPENSSH-17993953
  • published16 Jul 2026
  • disclosed23 Jun 2026

Introduced: 23 Jun 2026

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

How to fix?

Upgrade Echo:latest openssh to version 1:10.4p1-1+e2 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream openssh package and not the openssh package as distributed by Echo. See How to fix? for Echo:latest 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