Ubuntu Security Notices USN-8688-1 USN-8688-1: PAM vulnerability Publication date 27 August 2026 Overview A system hardening measure could be bypassed. Releases 24.04 LTS 22.04 LTS 20.04 LTS 18.04 LTS Open side navigation Close side navigation Packages Details Update instructions References 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 Ubuntu Pro Fix available with Ubuntu Pro . libpam-doc – 1.3.1-5ubuntu4.7+esm1 Ubuntu Pro Fix available with Ubuntu Pro . libpam-modules – 1.3.1-5ubuntu4.7+esm1 Ubuntu Pro Fix available with Ubuntu Pro . libpam-modules-bin – 1.3.1-5ubuntu4.7+esm1 Ubuntu Pro Fix available with Ubuntu Pro . libpam-runtime – 1.3.1-5ubuntu4.7+esm1 Ubuntu Pro Fix available with Ubuntu Pro . libpam0g – 1.3.1-5ubuntu4.7+esm1 Ubuntu Pro Fix available with Ubuntu Pro . libpam0g-dev – 1.3.1-5ubuntu4.7+esm1 Ubuntu Pro Fix available with Ubuntu Pro . 18.04 LTS bionic libpam-cracklib – 1.1.8-3.6ubuntu2.18.04.6+esm2 Ubuntu Pro Fix available with Ubuntu Pro . libpam-doc – 1.1.8-3.6ubuntu2.18.04.6+esm2 Ubuntu Pro Fix available with Ubuntu Pro . libpam-modules – 1.1.8-3.6ubuntu2.18.04.6+esm2 Ubuntu Pro Fix available with Ubuntu Pro . libpam-modules-bin – 1.1.8-3.6ubuntu2.18.04.6+esm2 Ubuntu Pro Fix available with Ubuntu Pro . libpam-runtime – 1.1.8-3.6ubuntu2.18.04.6+esm2 Ubuntu Pro Fix available with Ubuntu Pro . libpam0g – 1.1.8-3.6ubuntu2.18.04.6+esm2 Ubuntu Pro Fix available with Ubuntu Pro . libpam0g-dev – 1.1.8-3.6ubuntu2.18.04.6+esm2 Ubuntu Pro Fix available with Ubuntu Pro . Reduce your security exposure Ubuntu Pro provides ten-year security coverage to 25,000+ packages in Main and Universe repositories, and it is free for up to five machines. Get Ubuntu Pro References https://launchpad.net/bugs/2164901