PatchSiren cyber security CVE debrief

CVE-2026-5343 Drupal CVE debrief

A privilege escalation vulnerability exists in the Drupal SAML SSO - Service Provider module. The flaw stems from an improper check for unusual or exceptional conditions (CWE-754), allowing attackers to escalate privileges. Affected versions span from 0.0.0 through 3.1.3; version 3.1.4 contains the fix. The vulnerability was disclosed via official Drupal security advisory SA-CONTRIB-2026-031 on 2026-05-28. No known exploitation in ransomware campaigns has been reported, and the issue has not been added to CISA's Known Exploited Vulnerabilities catalog.

Vendor: Drupal
Product: SAML SSO - Service Provider
CVSS: HIGH 7.4
CISA KEV: Not listed in stored evidence
Original CVE published: 2026-05-28
Original CVE updated: 2026-05-29
Advisory published: 2026-05-28
Advisory updated: 2026-05-29

Who should care

Organizations running Drupal with SAML SSO - Service Provider module versions prior to 3.1.4, particularly those using SAML-based federated authentication for administrative or privileged user access. Security teams responsible for identity and access management infrastructure, Drupal site administrators, and compliance officers monitoring authentication control effectiveness.

Technical summary

The SAML SSO - Service Provider module for Drupal fails to properly validate exceptional conditions during SAML authentication processing. This improper check (CWE-754) can be exploited to escalate privileges beyond those intended for the authenticated user. The vulnerability affects all versions from initial release (0.0.0) through 3.1.3. The fix in version 3.1.4 adds proper validation of edge cases and exceptional conditions during the SAML assertion handling workflow. Organizations using this module for federated authentication should prioritize patching due to the direct impact on access control boundaries.

Defensive priority

high

Recommended defensive actions

Upgrade Drupal SAML SSO - Service Provider module to version 3.1.4 or later
Review user privilege assignments for unexpected administrative access
Monitor authentication logs for anomalous SAML assertion processing
Apply principle of least privilege to SAML-authenticated accounts
Verify SAML identity provider configuration integrity

Evidence notes

Official CVE record published 2026-05-28. Drupal security advisory SA-CONTRIB-2026-031 confirms affected versions and fix version. CWE-754 classification provided by NVD. No CVSS score or severity assigned at time of publication.

Official resources

2026-05-28