CVE-2026-47273

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.

At a glance

Exploitability

Can be exploited over the network without logging in. High risk of data tampering.

Exploit odds

0.3% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-05-27 20:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-10-26 11:10 UTC Last updatedMost recent change to the record

Details

Published

2026-05-27 20:16 UTC

Last modified

2026-10-26 11:10 UTC

Exploit probability

0.3% · EPSS, next 30 days

Weakness

CWE-91

Record status

Deferred

Attack profile CVSS 3.1 · 6.5

Attack vector

Network

Complexity

High

Privileges needed

None

User interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

High

Availability

None