CVE-2026-47273CWE-91

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

Medium · published May 27, 2026

CVSS v3.1
6.5
EPSS
0%
Percentile
34.1
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
6.5 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:N
CVSS v4.0
Not supplied
EPSS
0.00409 · 34.1th percentile
Weakness
CWE-91 · XML Injection (aka Blind XPath Injection)
Published
2026-05-27T20:03Z
EPSS history
Timeline
  • 27 MAY 20:03Z
    pam_usb: XPath injection via PAM-supplied identifiers in pam_usb configuration queries
    cvelistv5