CVE-2026-48066 pam_usb: Thread-unsafe static pointer in log.c causes data race under concurrent PAM authentication
- Exploited in the wild
- Not known
- Fix
- None listed
What is CVE-2026-48066?
CVE-2026-48066 is a medium-severity vulnerability in mcdope pam_usb, published on 27 May 2026.
Official 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.
Which versions are affected by CVE-2026-48066?
How do I fix CVE-2026-48066?
No fix has been published for CVE-2026-48066 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-48066 being exploited?
There is no known exploitation of CVE-2026-48066 in the wild and no public exploit code.
Sources
Also known as GHSA-qg76-57wq-mpv6.