CVE-2026-90462 Sssd: sssd: fail-open in ldap ppolicy access check allows continued authorization

Description

A flaw was found in SSSD. When configured with the LDAP access provider and `ldap_access_order` including `ppolicy` or `lockout`, a fail-open condition in the LDAP ppolicy access check can occur if a user lookup returns zero results. This can incorrectly return success and cache an allow decision, permitting continued authorization for a deleted or deprovisioned user. A remote attacker with prior valid account context could exploit this to maintain access to information and potentially make limited modifications to resources that should no longer be available.

Exploitable remotely over the network, with an ordinary account and without any user action; the impact on data or service is limited.

Attack vector

Network

Attack complexity

Low

Privileges required

Low

Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

Low

Availability

None

Affected products and versions