CVE-2026-87853
HIGH
MEDIUM
Priority: 0.02
BB Relevance:
55/100
Published: 2026-09-09
Modified: 2026-10-29
First seen: 2026-10-29
Status: active
Attack Surface
Network
No Interaction
Conf. Impact
Integ. Impact
CVSS Vector Breakdown
AV:
Network
AC:
High
PR:
Low
UI:
None
S:
Unchanged
C:
High
I:
High
A:
High
Description
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.