Drupal SAML SSO - Service Provider contains an improper check for unusual or exceptional conditions (CWE‑754, Improper Check for Unusual or Exceptional Conditions) that allows an attacker to bypass authentication and gain higher privileges, resulting in privilege escalation. The flaw directly undermines the authentication mechanism by permitting elevated access to users who should be denied.

All installations of Drupal SAML SSO - Service Provider with a version below 3.1.4 are affected. The issue was resolved in version 3.1.4, which includes the corrected authentication checks.

The CVSS score of 7.4 indicates high severity, while the EPSS score of less than 1% suggests low exploitation probability. The vulnerability is not listed in CISA KEV. The flaw could enable an attacker to gain unauthorized privileges; no definitive exploit is documented. Based on the description, the likely attack vector is remote access to the SAML SSO endpoint, but this inference is supported only by the fact that SAML exchanges occur over the network.