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.

• openssh (bug https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1143936) https://bugzilla.redhat.com/show_bug.cgi?id=2462250