Authentication bypass via ignored evdev permission errors
Published May 27, 2026 · Updated May 27, 2026
Protection mechanism failure in mcdope pam_usb before 0.9.1 allows local users to bypass remote-desktop detection during authentication. pusb_has_virtual_input_device() treats every EACCES failure while opening /dev/input/event* as an absent device, and src/local.c continues authentication on that false negative. Exploitation requires a reduced-privilege PAM execution context; normal root-invoked PAM operation is unaffected, while non-root pamusb-check validation can falsely report protection as active.
Summary
What happened
Protection mechanism failure in mcdope pam_usb before 0.9.1 allows local users to bypass remote-desktop detection during authentication. pusb_has_virtual_input_device() treats every EACCES failure while opening /dev/input/event* as an absent device, and src/local.c continues authentication on that false negative. Exploitation requires a reduced-privilege PAM execution context; normal root-invoked PAM operation is unaffected, while non-root pamusb-check validation can falsely report protection as active.
The record
- CVE
- CVE-2026-48792
- Published
- May 27, 2026
- Updated
- May 27, 2026
- Vendor
- mcdope
- Product
- pam_usb
- Classifications
- CWE-390, CWE-693
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- May 27, 2026CVE publishedPublication date reported by the CVE source.
- May 27, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 0.9.1
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo