VulnerabilityDeferred

CVE-2026-48982

pam_usb provides hardware authentication for Linux using ordinary removable media.

MEDIUM 5.8EPSS 0.12%

Does this matter?

Lower severity and a low EPSS score (0.12%). Track it; it rarely justifies an emergency change on its own.

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.

CVSS 3.1: 5.8 MEDIUMCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:H/A:L
EPSS: 0.12% probability · 2th percentile
CISA KEV: Not listed
Weakness: CWE-362
Source: security-advisories@github.com

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.