CVE-2026-44709

HIGH

pam_usb: PINENTRY_FALLBACK_APP environment variable allows arbitrary command execution

Title source: cna
STIX 2.1

Description

pam_usb provides hardware authentication for Linux using ordinary removable media. Prior to 0.8.7, pamusb-pinentry reads the PINENTRY_FALLBACK_APP environment variable and executes it directly without any validation. Any process that can set environment variables before pamusb-pinentry is invoked can point PINENTRY_FALLBACK_APP at an arbitrary binary or script and have it executed with the privileges of the pam_usb tool chain. This vulnerability is fixed in 0.8.7.

References (1)

Core 1
Core References

Scores

CVSS v3 7.8
EPSS 0.0015
EPSS Percentile 4.6%
Attack Vector LOCAL
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CISA SSVC

Vulnrichment
Exploitation poc
Automatable no
Technical Impact total

Details

CWE
CWE-78
Status published
Products (1)
mcdope/pam_usb < 0.8.7
Published May 27, 2026
Tracked Since May 28, 2026