CVE-2026-15981 SAML Single Sign On <= 5.4.4 - Unauthenticated Authentication Bypass via SAMLResponse Parameter

The SAML Single Sign On – SSO Login plugin for WordPress is vulnerable to Authentication Bypass in all versions up to, and including, 5.4.4. This is due to the mosamlvalidatesignature function performing a loose boolean check on the raw tri-state integer returned by PHP's opensslverify, causing a...