Vulnerability record/PUBLISHED/Published Jun 23, 2026 03:36:25 UTC
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.
Base score5.0/ 10
SeverityMediumCVSS 3.1
Exploitability / impact
CVSS metric breakdown
Base severityMedium
Attack vectorLocalAV
Attack complexityHighAC
Privileges requiredLowPR
User interactionRequiredUI
ScopeUnchangedS
Confidentiality impactHighC
Integrity impactLowI
Availability impactNoneA
CVSS vector string
CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:H/I:L/A:NCVSS communicates standardized severity and impact characteristics. It does not establish whether a system is exploitable in your specific environment.
Record context
CVE Numbering Authorityredhat
Last updatedOct 26, 2026 03:28:24 UTC
PublishedJun 23, 2026 03:36:25 UTC
ReservedJun 16, 2026 23:55:05 UTC
Credits
- This issue was discovered by In partnership with Red Hat (Aisle.com).