CVE-2026-55655
MEDIUM severity · CVSS 5 · CWE-923
5CVSS MEDIUM
Summary
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.
Impact & exploitability
Attack vectorLocal
Attack complexityHigh
Privileges requiredLow
User interactionRequired
Confidentiality impactHigh
Integrity impactLow
Availability impactNone
Exploit probability (EPSS)0%
CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:H/I:L/A:N
Affected products we track (2)
Recommendation
Apply the vendor fix in your normal patch cycle. Open any affected product above for its exact safe version.