pam_usb: Shell injection via device UUID and username in pamusb-conf and pamusb-agent

published 2026-05-27 5mo ago modified 2026-10-26 14d ago also EUVD-2026-32662

cvss: 8.2; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.2%; EPSS 0.2% chance of exploitation in 30 days, percentile 4%
public exploits: 0; none known

pam_usb provides hardware authentication for Linux using ordinary removable media. Prior to 0.8.7, a crafted UUID such as $(id>/tmp/rce) in the config causes root RCE when pamusb-conf --reset-pads is run. A USB device with a crafted filesystem UUID (some controllers allow this) can inject the payload at --add-device time. Also, userName from the XML config is passed to os.system() in pamusb-agent, which invokes a shell. This vulnerability is fixed in 0.8.7.

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CISA SSVC

Exploitation: none
Automatable: no
Technical impact: total
Assessed: 5mo ago (2026-05-28)

Exploit prediction

0.15% chance of exploitation in the next 30 days, higher than 4% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by	version	score	vector
CNA	3.1	8.2	CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

Affected products

mcdope pam_usb

Classification

Weakness

CWE-78 Improper Neutralization of Special Elements used in an OS Command
CWE-88 Improper Neutralization of Argument Delimiters in a Command

References

github.com /mcdope/pam_usb/security/advisories/GHSA-jgv5-w6rm-7wxg

Sources

CVE List CVE-2026-44712
NVD CVE-2026-44712

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