# CVE-2026-48065: mcdope pam_usb heap overflow in conf.c on 32-bit systems

Source: https://junglewise.ai/threats/cve-2026-48065-mcdope-pam-usb-heap-overflow-in-conf-c-on-32-bit-systems  
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-2026-48065 · Severity: medium · CVSS 6.7 · Published 2026-05-27

pam_usb is a tool that allows users to log into Linux systems using a USB flash drive instead of a password. A security flaw in how the software reads its configuration file on 32-bit systems could allow an attacker with administrative access to crash the system or potentially execute malicious code by corrupting system memory. This vulnerability is primarily a concern in environments where configuration files are automatically generated or where an attacker has already gained partial control of the system.

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

## Quick answers

**Is CVE-2026-48065 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-48065 being exploited in the wild.

**How severe is CVE-2026-48065?** Medium severity, with a CVSS score of 6.7, published 27 May 2026.

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

**Is there a fix for CVE-2026-48065?** A patch was published on 2026-05-27: Version 0.9.1 released Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-48065 attacked?** It is attacked with local access, in a software library.

**Am I affected by CVE-2026-48065?** 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 heap-based buffer overflow exists in pam_usb's configuration parser (src/conf.c) due to an integer overflow during memory allocation. The software uses libxml2 to count device nodes in the configuration file but fails to enforce an upper bound on the 'n_devices' variable. On 32-bit architectures (such as i686 or armv7l), the multiplication of 'n_devices' by the size of the device structure can wrap around size_t, resulting in a small allocation via xmalloc(). Subsequent writes to this undersized buffer lead to a heap overflow. Exploitation requires the ability to modify the root-owned pam_usb.conf file, limiting the attack to users with high privileges or through supply-chain configuration injection. The issue is fixed in version 0.9.1 by implementing a maximum device limit (PUSB_MAX_DEVICES).

## Affected products

- mcdope pam_usb <= 0.9.0

## Timeline

- 2021-03-01: other: Security audit initiated by maintainer
- 2026-05-19: disclosed: Issue reported on GitHub
- 2026-05-23: advisory: Project maintainer published security advisory GHSA-24mw-m2vf-36vp
- 2026-05-27: patched: Version 0.9.1 released

## References

- [https://github.com/mcdope/pam_usb/issues/352](https://github.com/mcdope/pam_usb/issues/352)
- [https://github.com/mcdope/pam_usb/issues/55](https://github.com/mcdope/pam_usb/issues/55)
- [https://github.com/mcdope/pam_usb/security/advisories/GHSA-24mw-m2vf-36vp](https://github.com/mcdope/pam_usb/security/advisories/GHSA-24mw-m2vf-36vp)

## Related threats

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- [mcdope pam_usb XXE in configuration file parsing](https://junglewise.ai/threats/cve-2026-48981-mcdope-pam-usb-xxe-in-configuration-file-parsing)