# CVE-2026-44713: mcdope pam_usb command injection in tmux.c

Source: https://junglewise.ai/threats/cve-2026-44713-mcdope-pam-usb-command-injection-in-tmux-c  
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-2026-44713 · Severity: high · CVSS 8.8 · Published 2026-05-27

pam_usb is a tool that allows users to log into Linux systems using a physical USB drive instead of a password. A security flaw in how it handles session information allows a local user to bypass the hardware requirement and execute commands with administrative (root) privileges. By setting a specially crafted environment variable, an attacker can trick the system into running malicious code during the login process, leading to a full system takeover.

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

## Quick answers

**Is CVE-2026-44713 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-44713 being exploited in the wild.

**How severe is CVE-2026-44713?** High severity, with a CVSS score of 8.8, published 27 May 2026.

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

**Is there a fix for CVE-2026-44713?** 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-2026-44713 attacked?** It is attacked with local access, in a software library.

**Am I affected by CVE-2026-44713?** 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 tmux remote-detection component of pam_usb (src/tmux.c). The software reads the user-controlled $TMUX environment variable and interpolates the socket-path component into a shell command string passed to popen() without proper sanitization. Because the variable is placed inside double-quotes, an attacker can use a double-quote character to terminate the string and inject arbitrary shell syntax. Since the PAM stack executes popen() with root privileges, a local attacker can achieve privilege escalation to root without possessing the required physical USB device. This issue is fixed in version 0.8.7 by implementing strict validation of the socket path and client ID.

## Affected products

- mcdope pam_usb < 0.8.7

## Timeline

- 2026-05-07: advisory: GitHub Security Advisory published
- 2026-05-27: disclosed: CVE published to NVD

## References

- [https://github.com/mcdope/pam_usb/security/advisories/GHSA-822m-whrh-vrj8](https://github.com/mcdope/pam_usb/security/advisories/GHSA-822m-whrh-vrj8)

## 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)