CVE-2026-48982
Severity CVSS v4.0:
Pending analysis
Type:
CWE-362
Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
Publication date:
18/06/2026
Last modified:
22/06/2026
Description
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.
Impact
Base Score 3.x
5.80
Severity 3.x
MEDIUM