CVE-2026-64667

What it is

pam_usb provides hardware authentication for Linux using removable media. Prior to version 0.9.3, src/local.c (pusb_get_tty_from_display_server) allocates a 4096-byte cmdline buffer, reads up to 4096 bytes from /proc//cmdline, then replaces every NUL separator with a space. When read(2) returns exactly 4096 bytes for any process the function inspects, the buffer ends without a terminator and the subsequent strstr() calls scan past the allocation boundary. The function is invoked during normal PAM authentication when DISPLAY is set, so the read fires for every process at auth time. Consequences are bounded: strstr output is a Boolean substring match (limited info-disclosure surface) but a hostile heap layout can produce a SIGSEGV that terminates the host PAM process. This issue has been patched in version 0.9.3.

At a glance

Exploitability

Can be exploited locally on the machine with a low-privilege account. Limited direct impact.

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-07-20 17:12 UTC ReservedThe CVE id was reserved by its CNA
2. 2026-11-11 05:19 UTC PublishedDisclosed publicly on CVE.org and NVD
3. 2026-11-11 05:19 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: not scored yet.
• Severity: 4.4 MEDIUM (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2026-11-11 05:19 UTC

Last modified

2026-11-11 05:19 UTC

Weakness

CWE-125 · Out-of-bounds read

Record status

Received

Attack profile CVSS 3.1 · 4.4

Attack vector

Local

Complexity

Low

Privileges needed

Low

User interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

None

Availability

Low

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-64667.md and follow it. Check whether this project is affected by CVE-2026-64667. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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