What’s Vulnerable › Vulnerabilities

CVE-2026-47273: pam_usb: XPath injection via PAM-supplied identifiers in pam_usb configuration queries

• Severity: medium (CVSS 6.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-05-27 · updated 2026-10-26
• Weakness: CWE-91

Description

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.

Affected products

• mcdope pam_usb: before 0.9.0

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

Get alerted when CVE-2026-47273 or the next vulnerability affects your stack