# CVE-2026-55655

## Summary

- **CVE ID:** CVE-2026-55655
- **Severity:** MEDIUM
- **CVSS Score:** 5 (CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:H/I:L/A:N)
- **CWE:** CWE-923
- **Published:** Jun 23, 2026
- **Last Modified:** Sep 1, 2026

## 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.

## Affected Products

- Red Hat — Red Hat Hardened Images (10.3p1-6.hum1)
- Red Hat — Red Hat Enterprise Linux 8 (0:8.0p1-30.el8_10)
- Red Hat — Red Hat Enterprise Linux 10 (0:9.9p1-25.el10_2)
- Red Hat — Red Hat Enterprise Linux 9 (0:9.9p1-9.el9_8)
- Red Hat — Red Hat Update Infrastructure 5 (1786435483)
- Red Hat — Red Hat Update Infrastructure 5 (1786533529)
- Red Hat — Red Hat Update Infrastructure 5 (1787135742)
- Red Hat — Red Hat Update Infrastructure 5 (1787241260)

## References

- [CNA](https://access.redhat.com/security/cve/CVE-2026-55655)
- [CNA](https://bugzilla.redhat.com/show_bug.cgi?id=2462250)
- [CNA](https://access.redhat.com/errata/RHSA-2026:36759)
- [CNA](https://access.redhat.com/errata/RHSA-2026:47755)
- [CNA](https://access.redhat.com/errata/RHSA-2026:47756)
- [CNA](https://access.redhat.com/errata/RHSA-2026:47757)
- [CNA](https://access.redhat.com/errata/RHSA-2026:54387)
- [CNA](https://access.redhat.com/errata/RHSA-2026:58981)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.09%
- **EPSS Percentile:** 0.4

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-11._