CVE-2026-48792
pam_usb: pusb_has_virtual_input_device() silently discards EACCES, disabling remote desktop detection under non-root execution
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.
INFO
Published Date :
May 27, 2026, 8:16 p.m.
Last Modified :
Oct. 26, 2026, 11:10 a.m.
Remotely Exploit :
No
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Update pam_usb to version 0.9.1.
- Ensure correct file permissions for /dev/input/event* nodes.
- Verify authentication logic handles permission errors.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-48792.
| URL | Resource |
|---|---|
| https://github.com/mcdope/pam_usb/issues/351 | |
| https://github.com/mcdope/pam_usb/issues/55 | |
| https://github.com/mcdope/pam_usb/security/advisories/GHSA-pvrg-chgw-x42c |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-48792 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-48792
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-48792 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-48792 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Translated by [email protected]
Oct. 26, 2026
Action Type Old Value New Value Added Translation Title: pam_usb de mcdope, Description: pam_usb proporciona autenticación de hardware para Linux utilizando medios extraíbles comunes. Antes de 0.9.1, src/evdev.c ignora silenciosamente los errores EACCES al abrir los nodos /dev/input/event, lo que provoca que pusb_has_virtual_input_device() devuelva 0 (no se encontraron dispositivos virtuales) incluso cuando cada llamada a open() falló debido a permisos insuficientes. El llamador en src/local.c no puede distinguir una ausencia limpia de dispositivos virtuales de un escaneo con permisos denegados, y actúa sobre el falso negativo al continuar la autenticación sin denegar. Esta vulnerabilidad está corregida en 0.9.1. -
CVE Modified by [email protected]
Jun. 17, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'mcdope', 'product': 'pam_usb', 'versions': [{'status': 'affected', 'version': '< 0.9.1'}]}] -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jun. 17, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-48792', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-05-28T13:27:27.036665Z'} -
New CVE Received by [email protected]
May. 27, 2026
Action Type Old Value New Value Added 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. Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N Added CWE CWE-693 Added CWE CWE-390 Added Reference https://github.com/mcdope/pam_usb/issues/351 Added Reference https://github.com/mcdope/pam_usb/issues/55 Added Reference https://github.com/mcdope/pam_usb/security/advisories/GHSA-pvrg-chgw-x42c