CVE-2026-48982: Mcdope Pam USB

Medium severity, CVSS 5.8. EPSS: 0.1% chance of exploitation in the next 30 days.

pam_usb provides hardware authentication for Linux using ordinary removable media. In versions prior to 0.9.2, when updating a one-time pad file, a temporary file is created using open() without the O_EXCL flag. Without O_EXCL, the create operation is not atomic: two concurrent processes racing to update the same pad may both succeed in opening the file, with the second write silently overwriting the first. The one-time pad is the core replay-prevention mechanism of pam_usb. A successful race could result in the stored pad value diverging from what either process expected, potentially causing authentication failures or, in a precisely timed attack, creating a window for pad reuse. This issue has been fixed in version 0.9.2.

Affected products

• Mcdope Pam USB: before 0.9.2 (fixed in 0.9.2)

Published 2026-06-18. Last modified 2026-06-22.