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.
History

Wed, 27 May 2026 21:00:00 +0000

Type Values Removed Values Added
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.
Title pam_usb: PINENTRY_FALLBACK_APP environment variable allows arbitrary command execution
Weaknesses CWE-78
References
Metrics cvssV3_1

{'score': 7.8, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-05-27T20:20:52.529Z

Reserved: 2026-05-07T17:07:09.318Z

Link: CVE-2026-44709

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-05-27T21:16:17.807

Modified: 2026-05-27T21:16:17.807

Link: CVE-2026-44709

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-05-27T22:30:35Z