CVE Database · CVE-2026-40458
CVSS v3.1
6.5
CVSS v4.0
7.0
EPSS
0.17%
Published
Apr 17, 2026
Modified
Apr 20, 2026
Public PoC / Exploit
All weaponized →No public PoC or exploit code indexed for this CVE.
Links to public security research (Exploit-DB, Nuclei, Trickest, GitHub) for defensive use only.
Description
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
CVSS Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:NWeaknesses (CWE)
References (2)