Local Hijacking Vulnerability in OpenSSH Affecting Linux Clients
CVE-2026-55655

5MEDIUM

Key Information:

Vendor

Red Hat
Status
Red Hat Enterprise Linux 10
Red Hat Enterprise Linux 6
Red Hat Enterprise Linux 7
Red Hat Enterprise Linux 8
Vendor
CVE Published:
23 June 2026

What is CVE-2026-55655?

A flaw in OpenSSH allows a local unprivileged attacker to hijack client-side X11 forwarding connections. This vulnerability arises when X11 forwarding is enabled and a local UNIX-domain X socket is utilized. The attacker can pre-bind the preferred abstract X socket name, which can lead to the compromise of the confidentiality of forwarded X11 traffic. This includes potential access to sensitive window contents and input manipulation of the forwarded session, posing a notable risk to user data and privacy.

References

https://access.redhat.com/security/cve/CVE-2026-55655
vdb-entryx_refsource_REDHAT
https://bugzilla.redhat.com/show_bug.cgi?id=2462250
issue-trackingx_refsource_REDHAT

CVSS V3.1

Score:
5
Severity:
MEDIUM
Confidentiality:
High
Integrity:
Low
Availability:
High
Attack Vector:
Local
Attack Complexity:
High
Privileges Required:
Low
User Interaction:
Required
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

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