Pac4j Pac4j vulnerabilities

CVE-2026-82465 Medium · 5.3 CWE-345 Aug 29, 2026

pac4j-saml before 6.5.6 Session Destruction via Unsigned LogoutRequest

pac4j-saml before 6.5.6 does not require signature validation of SAML LogoutRequest messages in SAML2LogoutValidator.validateLogoutRequest(). When an IdP sends no SessionIndex, a session can be destroyed based solely on the NameID, allowing an unauthenticated attacker to submit an unsigned LogoutRequest with a guessed identifier (e.g., an email address used as NameID) to terminate a victim's SAML session.

CVE-2026-82464 Medium · 6.1 CWE-601 Aug 29, 2026

pac4j-core before 6.5.6 Open Redirect via Backslash Logout

pac4j-core before 6.5.6 contains an open redirect vulnerability in DefaultLogoutLogic.perform() that accepts backslash-prefixed logout redirect targets matching logoutUrlPattern. Attackers can craft logout links with backslash-prefixed external hosts that browsers normalize into network-path references, redirecting victims to attacker-controlled sites after logout.

CVE-2026-82463 High · 8.1 CWE-863 Aug 29, 2026

pac4j-core before 6.5.6 Authorization Bypass via Reversed Profile Type Check

pac4j-core before 6.5.6 contains an authentication bypass vulnerability in CheckProfileTypeAuthorizer that reverses the profile type validation logic. Attackers can authenticate through a weaker client and access resources requiring a stronger profile type by satisfying generic profile checks.

CVE-2026-82462 Medium · 6.5 CWE-345 Aug 29, 2026

pac4j-oidc before 6.5.6 Authentication Bypass via Access Token Substitution

pac4j-oidc before 6.5.6 accepts OIDC callbacks carrying only an access token without authorization code or ID token validation. Attackers can substitute access tokens minted for other clients to create authenticated sessions without proper issuer, audience, nonce, or subject verification.

CVE-2026-82461 High · 8.1 CWE-347 Aug 29, 2026

pac4j-oidc before 6.5.6 Privilege Escalation via Unverified Keycloak Access Token

pac4j-oidc before 6.5.6 fails to verify access token signatures, issuers, audiences, or expiry when extracting Keycloak realm and client roles. Attackers can forge access tokens with administrative roles paired with valid ID tokens to bypass authorization checks in applications relying on pac4j role validation.

CVE-2026-40459 High · 8.8 CWE-90 Apr 17, 2026

LDAP Injection in PAC4J

PAC4J is vulnerable to LDAP Injection in multiple methods. A low-privileged remote attacker can inject crafted LDAP syntax into ID-based search parameters, potentially resulting in unauthorized LDAP queries and arbitrary directory operations. This issue was fixed in PAC4J versions 4.5.10, 5.7.10 and 6.4.1

CVE-2026-40458 Medium · 6.5 CWE-352 Apr 17, 2026

Cross-Site Request Forgery in PAC4J

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