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.

CVSS 3.1

6.5CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:N

EPSS

0.3% chance of exploitation in the next 30 days; higher than 19% of CVEs (scores of 2026-10-25)

CWE

CWE-91

Published

2026-05-27

Modified

2026-10-26

Record from

the NVD, synced 2026-10-26

References

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

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