pam_usb provides hardware authentication for Linux using ordinary removable media. Prior to 0.8.7, src/tmux.c reads the user's $TMUX environment variable, splits it on commas, and interpolates the socket-path component directly into a shell command passed to popen(). Because the value is placed inside double-quotes without sanitisation, any value containing " terminates the quoted string and injects arbitrary shell syntax. popen() runs as root inside the PAM stack. This vulnerability is fixed in 0.8.7.
History

Wed, 27 May 2026 21:00:00 +0000

Type Values Removed Values Added
Description pam_usb provides hardware authentication for Linux using ordinary removable media. Prior to 0.8.7, src/tmux.c reads the user's $TMUX environment variable, splits it on commas, and interpolates the socket-path component directly into a shell command passed to popen(). Because the value is placed inside double-quotes without sanitisation, any value containing " terminates the quoted string and injects arbitrary shell syntax. popen() runs as root inside the PAM stack. This vulnerability is fixed in 0.8.7.
Title pam_usb: Command injection via $TMUX environment variable leads to RCE as root
Weaknesses CWE-116
CWE-78
References
Metrics cvssV3_1

{'score': 8.8, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-05-27T20:13:13.193Z

Reserved: 2026-05-07T17:07:09.318Z

Link: CVE-2026-44713

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-05-27T21:16:18.363

Modified: 2026-05-27T21:16:18.363

Link: CVE-2026-44713

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-05-27T22:30:35Z