# CVE-2026-44709: pam_usb command injection in pamusb-pinentry

Source: https://junglewise.ai/threats/cve-2026-44709-pam-usb-command-injection-in-pamusb-pinentry  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-05-27. Updated: 2026-05-27  
License: CC BY 4.0 with a link back

CVE-2026-44709 · Severity: high · CVSS 7.8 · Published 2026-05-27

pam_usb is a tool that allows users to log into Linux systems using USB drives or other removable media instead of just passwords. A security flaw in its PIN entry component allows a local attacker to run unauthorized commands or scripts with elevated system privileges. Additionally, a separate issue could allow other users on the same computer to briefly see sensitive keyring passwords during the login process.

Technologies: [Mcdope Pam Usb](https://junglewise.ai/threats/technologies/pam-usb). Vendors: [Mcdope](https://junglewise.ai/threats/vendors/mcdope).

## Quick answers

**Is CVE-2026-44709 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-44709 being exploited in the wild.

**How severe is CVE-2026-44709?** High severity, with a CVSS score of 7.8, published 27 May 2026.

**Which products and versions are affected?** Mcdope Pam Usb < 0.8.7.

**Is there a fix for CVE-2026-44709?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-44709 attacked?** It is attacked with local access, in a software library.

**Am I affected by CVE-2026-44709?** Check whether you run Mcdope Pam Usb at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

A command injection vulnerability exists in the pamusb-pinentry component of pam_usb due to the insecure handling of the PINENTRY_FALLBACK_APP environment variable. The application retrieves this variable and passes it directly to subprocess.run() without validation, allowing a local attacker who can influence the process environment to execute arbitrary binaries with the privileges of the pam_usb toolchain. Additionally, the pamusb-keyring-unlock-gnome component was found to interpolate GNOME Keyring passwords into shell command strings, making them visible in the process list (/proc/<pid>/cmdline). These issues are addressed in version 0.8.7 by implementing strict path validation for the fallback application and passing passwords via stdin.

## Affected products

- mcdope pam_usb < 0.8.7

## Timeline

- 2026-05-07: advisory: Original GitHub advisory published
- 2026-05-27: disclosed: NVD publication date

## References

- [https://github.com/mcdope/pam_usb/security/advisories/GHSA-jxrj-q67x-wr4c](https://github.com/mcdope/pam_usb/security/advisories/GHSA-jxrj-q67x-wr4c)

## Related threats

- [pam_usb heap out-of-bounds read in display server handling](https://junglewise.ai/threats/cve-2026-64667-pam-usb-provides-hardware-authentication-for-linux-using)
- [pam_usb XRDP session bypass via environment variable](https://junglewise.ai/threats/cve-2026-64666-pam-usb-provides-hardware-authentication-for-linux-using)
- [mcdope pam_usb symlink race condition in pad directory creation](https://junglewise.ai/threats/cve-2026-48983-mcdope-pam-usb-symlink-race-condition-in-pad-directory-creation)
- [mcdope pam_usb race condition in one-time pad update](https://junglewise.ai/threats/cve-2026-48982-mcdope-pam-usb-race-condition-in-one-time-pad-update)
- [mcdope pam_usb XXE in configuration file parsing](https://junglewise.ai/threats/cve-2026-48981-mcdope-pam-usb-xxe-in-configuration-file-parsing)