Vulnerability in Pac4j

CVE-2026-82465

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.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-82465?
CVE-2026-82465 is a medium-severity vulnerability in Pac4j, classified under Insufficient Verification of Data Authenticity. CVSS score: 5.3/10. Published 2026-08-29.
How severe is CVE-2026-82465?
Medium severity. CVSS v3 base score is 5.3 out of 10.