Improper Restriction of Communication Channel to Intended Endpoints The advisory has been revoked - it doesn't affect any version of package openssh (opens in a new tab)

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Snyk IDSNYK-UBUNTU2604-OPENSSH-17427926
published29 Jun 2026
disclosed23 Jun 2026

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Introduced: 23 Jun 2026

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

Amendment

The Ubuntu security team deemed this advisory irrelevant for Ubuntu:26.04.

NVD Description

Note: Versions mentioned in the description apply only to the upstream openssh package and not the openssh package as distributed by Ubuntu.

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.