CVE-2026-55655

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.

Scoring

Severity
MEDIUM
CVSS base score
5
CVSS vector
CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:H/I:L/A:N
EPSS probability
0.09%
CWE
CWE-923
Published
2026-06-23
Last modified
2026-09-01

Affected products

Weakness type

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