# CVE-2026-47269: mcdope pam_usb access control bypass in deny_remote

Source: https://junglewise.ai/threats/cve-2026-47269-mcdope-pam-usb-access-control-bypass-in-deny-remote  
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-2026-47269 · Severity: high · CVSS 7.4 · Published 2026-05-27

pam_usb is a tool that allows users to log into Linux systems using a physical USB drive as a security key. A flaw in its remote-access protection allows attackers to bypass security restrictions when connecting over a network via SSH. If an attacker has physical access to a registered USB device, they can use it to log into a remote server even if the system is configured to block remote USB authentication, potentially leading to unauthorized access to sensitive data and systems.

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

## Quick answers

**Is CVE-2026-47269 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-47269 being exploited in the wild.

**How severe is CVE-2026-47269?** High severity, with a CVSS score of 7.4, published 27 May 2026.

**Which products and versions are affected?** Mcdope Pam Usb < 0.9.0.

**Is there a fix for CVE-2026-47269?** A patch was published on 2026-05-27: Fixed in version 0.9.0 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-47269 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-47269?** 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 vulnerability exists in pam_usb's 'deny_remote' feature due to an incomplete check of the utmpx ut_addr_v6 field. The software originally only validated the first 32-bit word of the 128-bit IPv6 address field to detect remote sessions. Because IPv4-mapped IPv6 addresses (::ffff:x.x.x.x) store the address data in the final word and leave the first word as zero, remote connections on systems using IPv6 wildcards (common in Debian/Ubuntu SSH configurations) are misclassified as local. An attacker with physical access to a registered USB device can exploit this to authenticate via SSH, bypassing the intended remote-access block. This issue is resolved in version 0.9.0 by ensuring all four words of the address field are checked.

## Affected products

- mcdope pam_usb < 0.9.0

## Timeline

- 2026-05-20: advisory: GitHub Security Advisory published
- 2026-05-27: disclosed: CVE-2026-47269 published to NVD
- 2026-05-27: patched: Fixed in version 0.9.0

## References

- [https://github.com/mcdope/pam_usb/commit/804fe24eae3d742d8be05fd015e36abc3c7d94e5](https://github.com/mcdope/pam_usb/commit/804fe24eae3d742d8be05fd015e36abc3c7d94e5)
- [https://github.com/mcdope/pam_usb/security/advisories/GHSA-jmmj-qhrq-w45g](https://github.com/mcdope/pam_usb/security/advisories/GHSA-jmmj-qhrq-w45g)

## 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)