CVE-2026-87853

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.

CVSS v3 7.5 HIGH

7.5^/10

CVSS v3 : HIGH

Vector :

Exploitability : 1.6 / Impact : 5.9

Attack Vector NETWORK

Attack Complexity HIGH

Privileges Required LOW

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://access.redhat.com/security/cve/CVE-2026-87853
https://bugzilla.redhat.com/show_bug.cgi?id=2530888

Configurations

No configuration.

History

No history.

Information

Published : 2026-09-09 17:17

Updated : 2026-09-10 15:17

NVD link : CVE-2026-87853

Mitre link : CVE-2026-87853

CVE.ORG link : CVE-2026-87853

JSON object : View

Products Affected

No product.

CWE

CWE-187

Partial String Comparison

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