CVE-2026-55655
Published: June 24, 2026Last modified: July 15, 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.
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 6.1 |
| Attack Vector | LOCAL |
| Attack complexity | LOW |
| Privileges required | NONE |
| User interaction | REQUIRED |
| Scope | UNCHANGED |
| Confidentiality | HIGH |
| Integrity impact | LOW |
| Availability impact | NONE |
| Vector | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:L/A:N |
Status
| Product | Release | Package | Status |
|---|---|---|---|
| Alpaquita Linux | 23 LTS | openssh | Not affected (9.1_p1-r3) |
| 25 LTS | openssh | Not affected (10.0_p1-r7) | |
| Stream | openssh | Not affected (9.3_p1-r7) | |
| Hardened Containers | 23 LTS | openssh | Not affected (9.1_p1-r3) |
| 25 LTS | openssh | Not affected (10.0_p1-r7) | |
| Stream | openssh | Not affected (9.3_p1-r7) |