CVE-2026-55655
Openssh: local mitm of x11 forwarding via abstract unix socket pre-binding in red hat enterprise linux openssh client versions
Published: Jun 23, 2026Updated: Jun 23, 2026 Sources: CVE ListCWE-923Improper Restriction of Communication Channel to Intended Endpoints
5.0CVSSMEDIUM
Description
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.
CVSS Vector Breakdown
Exploitability
AV:LAttack VectorLocal
AC:HAttack ComplexityHigh
PR:LPrivileges RequiredLow
UI:RUser InteractionRequired
Scope
S:UScopeUnchanged
Impact
C:HConfidentialityHigh
I:LIntegrityLow
A:NAvailabilityNone
Weaknesses
Affected Products
and 2 more affected products View all →
Exploitability
Workaround Available
References
Unlock Complete Vulnerability Intelligence
Get the full picture for CVE-2026-55655 and every CVE in our database. Create a free account — no credit card required.
Create Free AccountPlain-language analysis
Impact assessment and exploitation scenario in plain English
Attack graph visualization
Interactive attack path and kill chain mapping
Exploit details & PoC links
ExploitDB, Metasploit, GitHub PoCs with direct links
Nuclei scanner templates
Ready-to-use vulnerability scanner templates
Full remediation guide
Patch instructions, workarounds, and compliance impact
Interactive AI chat
Ask questions about this vulnerability in natural language
Related vulnerabilities
Semantically similar CVEs and attack patterns
REST API & MCP access
Integrate vulnerability data into your workflows