Vulnerability · Published Jun 14, 2026 · Assigned by TuranSec
CVE-2026-54411Linux-PAM pam_userdb Observable Timing Discrepancy in Plaintext Password Comparison
Medium 5.9
In plain English
A medium-severity security flaw in Linux-PAM from Linux-PAM. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 25% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux:10 | pam | 1.6.1-9.el10_2.1 | ALSA-2026:59379 |
| AlmaLinux:8 | pam | 1.3.1-40.el8_10 | ALSA-2026:56131 |
| AlmaLinux:9 | pam | 1.5.1-28.el9_8.1 | ALSA-2026:64815 |
| AlmaLinux:10 | pam-devel | 1.6.1-9.el10_2.1 | ALSA-2026:59379 |
| AlmaLinux:8 | pam-devel | 1.3.1-40.el8_10 | ALSA-2026:56131 |
| AlmaLinux:9 | pam-devel | 1.5.1-28.el9_8.1 | ALSA-2026:64815 |
| AlmaLinux:9 | pam-docs | 1.5.1-28.el9_8.1 | ALSA-2026:64815 |
| AlmaLinux:10 | pam-libs | 1.6.1-9.el10_2.1 | ALSA-2026:59379 |
| Debian:12 | pam | no fix listed | DEBIAN-CVE-2026-54411 |
| Debian:13 | pam | no fix listed | DEBIAN-CVE-2026-54411 |
| Debian:14 | pam | no fix listed | DEBIAN-CVE-2026-54411 |
| Rocky Linux:10 | pam | 0:1.6.1-9.el10_2.1 | RLSA-2026:59379 |
| Rocky Linux:8 | pam | 0:1.3.1-40.el8_10 | RLSA-2026:56131 |
| Rocky Linux:9 | pam | 0:1.5.1-28.el9_8.1 | RLSA-2026:64815 |
| Ubuntu:22.04:LTS | pam | 1.4.0-11ubuntu2.7 | UBUNTU-CVE-2026-54411 |
| Ubuntu:22.04:LTS | pam | 1.4.0-11ubuntu2.7 | USN-8601-1 |
| Ubuntu:24.04:LTS | pam | 1.5.3-5ubuntu5.6 | USN-8601-1 |
| Ubuntu:24.04:LTS | pam | 1.5.3-5ubuntu5.6 | UBUNTU-CVE-2026-54411 |
| Ubuntu:25.10 | pam | no fix listed | UBUNTU-CVE-2026-54411 |
| Ubuntu:26.04:LTS | pam | 1.7.0-5ubuntu3.1 | USN-8601-1 |
| Ubuntu:26.04:LTS | pam | 1.7.0-5ubuntu3.1 | UBUNTU-CVE-2026-54411 |
Affected products (as reported)
Weakness: CWE-208 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N