CVE-2026-47272
HIGH
MEDIUM
Priority: 0.01
BB Relevance:
39/100
Published: 2026-05-27
Modified: 2026-10-26
First seen: 2026-10-29
Status: active
Attack Surface
Low Complexity
No Interaction
Conf. Impact
Integ. Impact
CVSS Vector Breakdown
AV:
Local
AC:
Low
PR:
Low
UI:
None
S:
Unchanged
C:
High
I:
High
A:
None
Description
pam_usb provides hardware authentication for Linux using ordinary removable media. Prior to 0.9.0, the pusb_pad_compare() function in src/pad.c only verified that the user-side pad (~/.pamusb/device.pad) could be read, but did not enforce that the system-side pad (the pad file on the USB device) was also present and readable. If the user-side pad was deleted or unreadable, the function returned a failure that was treated as non-fatal in certain code paths, allowing authentication to succeed without the USB device being verified. A local user can delete their own ~/.pamusb/device.pad to remove the USB device requirement and authenticate without the physical device. This vulnerability is fixed in 0.9.0.