Skip to main content
VulnerabilityPublished Updated

CVE-2026-48982: mcdope pam_usb · Race Condition

Affects mcdope pam_usbSource CVE Database V5

0
Compare

Not known to be exploited · CVSS 5.8 Medium : upgrade to 0.9.2 when convenient.

Data as of 31 Oct 2026, 08:20 UTC

CVSS 3.1 base score
5.8Medium
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.1% chance of exploitation in 30 days – higher than 1% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in 0.9.2
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:H/A:L

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 18 Jun 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponized: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.

What to do

Upgrade pam_usb and mcdope/pam_usb to 0.9.2.

Affected software

ProductAffectedFixed in
mcdopepam_usbAffected
  • <0.9.2
Fixed in
  • 0.9.2
GitHubmcdope/pam_usbpkg:github/mcdope/pam_usbOther threatsAffected
  • <0.9.2
Fixed in
  • 0.9.2

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Upgrade pam_usb to version 0.9.2 or later, where the race condition has been fixed by ensuring atomic file creation with the O_EXCL flag. No other mitigations are indicated.

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.

References

Community reviews

Loading reviews…