CVE-2026-48066

MEDIUM

pam_usb: Thread-unsafe static pointer in log.c causes data race under concurrent PAM authentication

Title source: cna
STIX 2.1

Description

pam_usb provides hardware authentication for Linux using ordinary removable media. Prior to 0.9.1, src/log.c contains a process-wide static pointer that is written on every PAM invocation with the address of a stack-local variable. This violates the PAM re-entrancy requirement and creates a data race when the PAM stack is invoked concurrently from multiple threads. This vulnerability is fixed in 0.9.1.

References (3)

Core 3
Core References
X_Refsource_Misc x_refsource_misc
https://github.com/mcdope/pam_usb/issues/350
X_Refsource_Misc x_refsource_misc
https://github.com/mcdope/pam_usb/issues/55

Scores

CVSS v3 5.7
EPSS 0.0012
EPSS Percentile 1.9%
Attack Vector LOCAL
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact partial

Details

CWE
CWE-362 CWE-476
Status published
Products (1)
mcdope/pam_usb < 0.9.1
Published May 27, 2026
Tracked Since May 28, 2026