CVE-2026-82465

Medium

Description

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.

SeverityMedium

CVSS5.3

Exploit probability—

ProductPac4j

PublishedAug 29, 2026

First seenAug 29, 2026

Weakness typeCWE-345CWE-345

How to fix

Update

pac4j pac4j6.5.6 or later

Patches

github.com/pac4j/pac4j/commit/2270c3ff70e93cc43831e75702acd5135531237e

Vendor advisories

pac4j.org/blog/security-advisory-pac4j-core-oidc-saml.html

Affected products

Product	Affected versions	Fixed in
pac4j pac4j	v < 6.5.6	6.5.6

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