CVE-2026-87853
Sssd: sssd: idp authentication prefix comparison allows cross-user impersonation
CVSS 3.1 7.5 HIGHCheck source for fixed versionsKEV status unknown
cve-program · CVE-2026-87853
PublishedA 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.
Read the publisher's advisoryAffected versions, risk and source history
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CVE-2026-87853 · CVE overview and exploitation status
cve-program · CVE-2026-87853
Related changes
Linked by CVE identifier- Sssd: sssd: idp authentication prefix comparison allows cross-user impersonation · Affected-version evidence changed · 11 Nov 2026
- Sssd: sssd: idp authentication prefix comparison allows cross-user impersonation · Affected-version evidence changed · 6 Nov 2026
- Sssd: sssd: idp authentication prefix comparison allows cross-user impersonation · Affected-version evidence changed · 3 Nov 2026
- Sssd: sssd: idp authentication prefix comparison allows cross-user impersonation · Affected-version evidence changed · 29 Oct 2026