USN-8688-1: PAM vulnerability

Publication date

27 August 2026

Overview

A system hardening measure could be bypassed.


Packages

  • pam - Pluggable Authentication Modules

Details

Juthawong Naisanguansee discovered that PAM incorrectly cleared failed
login attempt records when certain services invoked the account phase
without first performing authentication. An attacker could possibly use
this issue to reset failed login counters, resulting in authentication
lockout restrictions being bypassed.

Juthawong Naisanguansee discovered that PAM incorrectly cleared failed
login attempt records when certain services invoked the account phase
without first performing authentication. An attacker could possibly use
this issue to reset failed login counters, resulting in authentication
lockout restrictions being bypassed.

Update instructions

After a standard system update you need to reboot your computer to make all the necessary changes.

Learn more about how to get the fixes.

The problem can be corrected by updating your system to the following package versions:

Ubuntu Release Package Version
24.04 LTS noble libpam-doc –  1.5.3-5ubuntu5.7
libpam-modules –  1.5.3-5ubuntu5.7
libpam-modules-bin –  1.5.3-5ubuntu5.7
libpam-runtime –  1.5.3-5ubuntu5.7
libpam0g –  1.5.3-5ubuntu5.7
libpam0g-dev –  1.5.3-5ubuntu5.7
22.04 LTS jammy libpam-cracklib –  1.4.0-11ubuntu2.8
libpam-doc –  1.4.0-11ubuntu2.8
libpam-modules –  1.4.0-11ubuntu2.8
libpam-modules-bin –  1.4.0-11ubuntu2.8
libpam-runtime –  1.4.0-11ubuntu2.8
libpam0g –  1.4.0-11ubuntu2.8
libpam0g-dev –  1.4.0-11ubuntu2.8
20.04 LTS focal libpam-cracklib –  1.3.1-5ubuntu4.7+esm1  
libpam-doc –  1.3.1-5ubuntu4.7+esm1  
libpam-modules –  1.3.1-5ubuntu4.7+esm1  
libpam-modules-bin –  1.3.1-5ubuntu4.7+esm1  
libpam-runtime –  1.3.1-5ubuntu4.7+esm1  
libpam0g –  1.3.1-5ubuntu4.7+esm1  
libpam0g-dev –  1.3.1-5ubuntu4.7+esm1  
18.04 LTS bionic libpam-cracklib –  1.1.8-3.6ubuntu2.18.04.6+esm2  
libpam-doc –  1.1.8-3.6ubuntu2.18.04.6+esm2  
libpam-modules –  1.1.8-3.6ubuntu2.18.04.6+esm2  
libpam-modules-bin –  1.1.8-3.6ubuntu2.18.04.6+esm2  
libpam-runtime –  1.1.8-3.6ubuntu2.18.04.6+esm2  
libpam0g –  1.1.8-3.6ubuntu2.18.04.6+esm2  
libpam0g-dev –  1.1.8-3.6ubuntu2.18.04.6+esm2  

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