CVE-2026-68743 Details

A denial-of-service vulnerability has been identified in the System Security Services Daemon (SSSD) within the Pluggable Authentication Module (PAM) responder. The issue arises in the extract_authtok_v1() function, which fails to properly validate the auth_token_length field against the available buffer size before processing. This flaw can be exploited by a local attacker who sends a crafted protocol v1 request to the PAM responder socket, leading to an out-of-bounds read, causing a process crash and disrupting SSSD-mediated authentication. On SSSD versions 2.10 and later, the PAM responder runs as an unprivileged user, while earlier versions may run as root. However, in all cases, the vulnerability causes a significant authentication outage for users managed by SSSD.