CVE-2026-54411

high

Description

Linux-PAM through 1.7.2 contains an observable timing discrepancy (CWE-208) in the pam_userdb module's plaintext-password comparison path in modules/pam_userdb/pam_userdb.c that allows a local or network-adjacent attacker able to repeatedly drive authentication through a calling service to recover the plaintext password of a target account by measuring response-timing differences.

References

https://github.com/linux-pam/linux-pam/blob/master/modules/pam_userdb/pam_userdb.c#L327

https://github.com/linux-pam/linux-pam/blob/master/libpam/include/pam_inline.h

https://github.com/linux-pam/linux-pam

https://cwe.mitre.org/data/definitions/208.html

Details

Source: Mitre, NVD

Published: 2026-06-14

Updated: 2026-08-10

Risk Information

CVSS v2

Base Score: 5.4

Vector: CVSS2#AV:N/AC:H/Au:N/C:C/I:N/A:N

Severity: Medium

CVSS v3

Base Score: 5.9

Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

Severity: Medium

CVSS v4

Base Score: 8.2

Vector: CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

Severity: High

EPSS

EPSS: 0.0032