CVE-2026-87853 — Sssd: sssd: idp authentication prefix comparison allows cross-user impersonation
A flaw was found in SSSD's IdP authentication provider. The eval_access_token_buf() function compares the OIDC subject identifier using strncmp() with the authenticated user's i…
Published: 2026-09-09 · CVSS: 7.5 · CVSS 3.1
A flaw was found in SSSD's IdP authentication provider. The eval_access_token_buf() 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 of a target user's identifier can authenticate as the target user.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7