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CVE-2026-48983

MEDIUM
5.8
CVSS 3.1
Description
pam_usb provides hardware authentication for Linux using ordinary removable media. In versions prior to 0.9.2, a symlink race condition exists in per-device and per-user pad directory creation. pam_usb uses a check-then-act pattern: it calls lstat() to test for existence and then calls mkdir() separately to create the directory. A local attacker can win the race between these calls by replacing the target path with a symlink to a directory they control. If successful, one-time pad files may be written to an attacker-controlled location, potentially exposing future pad values before use or disrupting authentication. This issue has been fixed in version 0.9.2.

Metadata

CVE ID
CVE-2026-48983
State
PUBLISHED
Assigner
GitHub_M
Reserved
2026-05-26 23:26 UTC
Published
2026-06-18 19:07 UTC
Last updated
2026-06-18 19:07 UTC
Primary CWE
CWE-367
CWE-367: Time-of-check Time-of-use (TOCTOU) Race Condition
Vendor / Product
mcdope / pam_usb
Sources
cve.org  ·  NVD

Severity & Metrics

5.8 MEDIUM CVSS 3.1
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:L/A:L
Affected products (1)
VendorProductPlatformVersions
mcdope pam_usb — < 0.9.2
Weakness (CWE)
CWESourceDescription
CWE-367 cna CWE-367: Time-of-check Time-of-use (TOCTOU) Race Condition
CVSS scores (1)
ScoreSeverityVersionSourceVector
5.8 MEDIUM 3.1 cna CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:L/A:L
References (2)
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