# CVE-2026-48064: mcdope pam_usb incorrect authorization in remote host check

Source: https://junglewise.ai/threats/cve-2026-48064-mcdope-pam-usb-incorrect-authorization-in-remote-host-check  
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-2026-48064 · Severity: high · CVSS 8.1 · 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 how it handles remote connections allows attackers to bypass security checks that are supposed to ensure the user is physically present at the machine. If a system is configured to allow remote logins (such as via XDMCP), an attacker with a stolen or cloned USB device could potentially log in remotely, bypassing the intended physical security requirement.

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

## Quick answers

**Is CVE-2026-48064 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-48064 being exploited in the wild.

**How severe is CVE-2026-48064?** High severity, with a CVSS score of 8.1, published 27 May 2026.

**Which products and versions are affected?** Mcdope Pam Usb < 0.9.1.

**Is there a fix for CVE-2026-48064?** A patch was published on 2026-05-27: Fixed in version 0.9.1 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-48064 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-48064?** 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

In pam_usb versions prior to 0.9.1, the PAM_RHOST check in the pusb_do_auth() function is incorrectly nested within a conditional block that only executes if 'deny_remote' is enabled. When 'deny_remote' is set to false (a common configuration for display managers like GDM or LightDM to avoid local TTY heuristic issues), the module fails to verify if the connection is originating from a remote host. This allows remote daemons that set PAM_RHOST, such as XDMCP or SSH, to proceed to the USB device authentication phase instead of being rejected. An attacker possessing a valid USB token and user credentials could exploit this to gain remote access to systems that were intended to only allow local USB-based logins. The issue is resolved in version 0.9.1 by decoupling the PAM_RHOST check from the 'deny_remote' configuration option.

## Affected products

- mcdope pam_usb < 0.9.1

## Timeline

- 2026-05-19: other: Issue first reported on GitHub
- 2026-05-23: advisory: Project maintainer published security advisory GHSA-w38v-cw9r-x9p6
- 2026-05-27: disclosed: CVE-2026-48064 published
- 2026-05-27: patched: Fixed in version 0.9.1

## References

- [https://github.com/mcdope/pam_usb/issues/348](https://github.com/mcdope/pam_usb/issues/348)
- [https://github.com/mcdope/pam_usb/security/advisories/GHSA-w38v-cw9r-x9p6](https://github.com/mcdope/pam_usb/security/advisories/GHSA-w38v-cw9r-x9p6)

## 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)
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- [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)