CVE-2026-87853

A flaw was found in SSSD's IdP authentication provider. The evalaccesstokenbuf function compares the OIDC subject identifier using strncmp with the authenticated user's identifier length, performing a prefix comparison instead of an exact match. An attacker whose IdP identifier is a strict prefix...

CVE-2026-87853 Sssd: sssd: idp authentication prefix comparison allows cross-user impersonation

A flaw was found in SSSD's IdP authentication provider. The evalaccesstokenbuf function compares the OIDC subject identifier using strncmp with the authenticated user's identifier length, performing a prefix comparison instead of an exact match. An attacker whose IdP identifier is a strict prefix...