CVE-2026-47274CWE-427

pam_usb: Uncontrolled search path in pam_usb tools allows privilege escalation via PATH manipulation

Medium · published May 27, 2026

CVSS v3.1
6.3
EPSS
0%
Percentile
7.0
In the wild
Unconfirmed
What it is

pam_usb provides hardware authentication for Linux using ordinary removable media. Prior to 0.9.0, multiple pam_usb helper tools resolved external binaries through the PATH environment variable rather than using absolute paths. An attacker who can influence the process environment during PAM authentication or tool execution could substitute malicious binaries. The affected tools are pamusb-check (src/tmux.c), pamusb-conf (tools/pamusb-conf), and pamusb-keyring-unlock-gnome (tools/pamusb-keyring-unlock-gnome). This vulnerability is fixed in 0.9.0.

The record
Technical detail
CVSS v3.1
6.3 · MEDIUM
Vector
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N
CVSS v4.0
Not supplied
EPSS
0.00178 · 7.0th percentile
Weakness
CWE-427 · Uncontrolled Search Path Element
Published
2026-05-27T20:02Z
EPSS history
Timeline
  • 27 MAY 20:02Z
    pam_usb: Uncontrolled search path in pam_usb tools allows privilege escalation via PATH manipulation
    cvelistv5