CVE-2026-55655
MEDIUMOpenssh: local mitm of x11 forwarding via abstract unix socket pre-binding in red hat enterprise linux openssh client versions
Title source: cnaDescription
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 (3)
Core 3
Core References
Vdb Entry, X_Refsource_Redhat vdb-entry
x_refsource_redhat
https://access.redhat.com/security/cve/CVE-2026-55655
Issue Tracking, X_Refsource_Redhat issue-tracking
x_refsource_redhat
RHBZ#2462250
https://bugzilla.redhat.com/show_bug.cgi?id=2462250
Vendor Advisory vendor-advisory
x_refsource_redhat
RHSA-2026:36759
https://access.redhat.com/errata/RHSA-2026:36759
Scores
CVSS v3
5.0
EPSS
0.0009
EPSS Percentile
0.6%
Attack Vector
LOCAL
CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:H/I:L/A:N
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
no
Technical Impact
partial
Details
CWE
CWE-923
Status
published
Products (14)
openbsd/openssh
Red Hat/Red Hat Enterprise Linux 10
Red Hat/Red Hat Enterprise Linux 6
Red Hat/Red Hat Enterprise Linux 7
Red Hat/Red Hat Enterprise Linux 8
Red Hat/Red Hat Enterprise Linux 9
Red Hat/Red Hat Hardened Images
Red Hat/Red Hat Hardened Images
10.3p1-6.hum1
Red Hat/Red Hat OpenShift Container Platform 4
redhat/enterprise_linux
6.0
... and 4 more
Published
Jun 23, 2026
Tracked Since
Jun 23, 2026