Vulnerability in Mcdope Pam Usb
CVE-2026-48982
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.
Vulnerability class: Race Condition
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.8 (Medium). Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:H/A:L.
EPSS exploit prediction
EPSS: 0.001 (1.5th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 2nd percentile — 1.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.001 · newest: 0.001 · change: 0.000
Affected products
- Mcdope Pam Usb — versions < 0.9.2
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2026-48982?
- CVE-2026-48982 is a medium-severity vulnerability in Mcdope Pam Usb, classified under Concurrent Execution using Shared Resource with Improper Synchronization (Race Condition). CVSS score: 5.8/10. Published 2026-06-18.
- How severe is CVE-2026-48982?
- Medium severity. CVSS v3 base score is 5.8 out of 10.