CVE-2026-68743 Sssd: sssd: pam responder out-of-bounds read via unchecked auth_token_length in protocol v1

Description

A flaw was found in SSSD. The extract_authtok_v1() function in the PAM responder does not validate the auth_token_length field against the remaining buffer size before processing. A local attacker can exploit this via a crafted protocol v1 request to the PAM responder socket, causing an out-of-bounds read and process crash, resulting in a denial of service.

Exploitable with local access to the machine, with an ordinary account and without any user action; an attacker can seriously compromise confidentiality, integrity or availability.

Attack vector

Local

Attack complexity

Low

Privileges required

Low

Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Affected products and versions