CVE-2026-44710

pam_usb: NULL pointer dereference from UDisks device fields causes PAM crash and login denial-of-service

MEDIUM
4.6
CVSS Score
Published: May 27, 2026 at 08:19 PM UTC
Updated: October 26, 2026 at 12:10 PM UTC
1 product affected across 1 vendorPam USB

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Severity
MEDIUM4.6
Exploit prediction
EPSS 0.2%
SSVC
No known exploit

Description

pam_usb provides hardware authentication for Linux using ordinary removable media. Prior to 0.8.7, src/device.c passed the return values of udisks_drive_get_serial(), udisks_drive_get_vendor(), and udisks_drive_get_model() directly to strcmp() without NULL checks. The GIO/UDisks API documentation states these accessors can return NULL for devices that do not expose the corresponding field. Passing NULL to strcmp() is undefined behaviour (typically a SIGSEGV). This vulnerability is fixed in 0.8.7.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 0.8.7
Affected range stops below 0.8.7, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

References (1)

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

4.6MEDIUMGitHub_M
Attack Vector
PHYSICAL
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-476

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