---
id: CVE-2026-82465
title: >-
  pac4j-saml before 6.5.6 does not require signature validation of SAML
  LogoutRequest messages in SAML2LogoutValidator.validateLogoutRequest()
summary: >-
  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, allow…
severity: medium
cvss: 5.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L'
cwe:
  - CWE-345
published: '2026-08-29'
updated: '2026-09-10'
sourceUpdated: '2026-09-10T19:54:25.810'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-82465'
references:
  - url: 'https://github.com/pac4j/pac4j'
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/pac4j/pac4j/blob/pac4j-parent-6.5.5/pac4j-saml/src/main/java/org/pac4j/saml/logout/impl/SAML2LogoutValidator.java
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/pac4j/pac4j/commit/2270c3ff70e93cc43831e75702acd5135531237e
    label: disclosure@vulncheck.com
  - url: 'https://www.pac4j.org/blog/security-advisory-pac4j-core-oidc-saml.html'
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/pac4j-saml-before-6.5.6-session-destruction-via-unsigned-logoutrequest
    label: disclosure@vulncheck.com
tags:
  - nvd
epss: 0.00263
epssPercentile: 0.16183
ingestedAt: '2026-08-30T12:52:23.686Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.