cvedb.io
CVE-2026-40458
MEDIUM · CVSS 6.5
EPSS exploitation probability: 0%
Published 2026-04-17T14:16:33.987 · Last modified 2026-06-17T10:45:19.557

Summary

PAC4J is vulnerable to Cross-Site Request Forgery (CSRF). A malicious attacker can craft a specially designed website which, when visited by a user, will automatically submit a forged cross-site request with a token whose hash collides with the victim's legitimate CSRF token. Importantly, the attacker does not need to know the victim’s CSRF token or its hash prior to the attack. Collisions in the deterministic String.hashCode() function can be computed directly, reducing the effective token's security space to 32 bits. This bypasses CSRF protection, allowing profile updates, password changes, account linking, and any other state-changing operations to be performed without the victim's consent. This issue was fixed in PAC4J versions 5.7.10 and 6.4.1

Affected products

pac4j — pac4j

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.