CVE-2026-47273

pam_usb provides hardware authentication for Linux using ordinary removable media. Prior to 0.9.0, pam_usb builds XPath expressions from user-supplied identifiers (PAM username, service name) and device-supplied identifiers (USB device serial, model, vendor) to query /etc/pamusb.conf. These identifiers were not validated for XPath metacharacters, allowing injection of arbitrary XPath predicates. This vulnerability is fixed in 0.9.0.

Score

CVSS 3.1 6.5 Medium

Status

Deferred - security-advisories@github.com

Published

2026-05-27

Last modified

2026-10-26

Weaknesses

CWE-91

Affected products

• Pam Usb (Mcdope)

References

• https://github.com/mcdope/pam_usb/security/advisories/GHSA-vfj3-5h5v-6g93
• https://github.com/mcdope/pam_usb/pull/311
• https://github.com/mcdope/pam_usb/commit/721fed08a3596cb5b4671ad702f8fdc12dcc7420