Vulnerability in SAML Single Sign On – SSO Login — CVE-2026-75807
What to do now
Update SAML Single Sign On – SSO Login to 5.4.7 or later.
Affected versions
- Everything up to and including 5.4.6
Affected: SAML Single Sign On – SSO Login (plugin, miniorange-saml-20-single-sign-on)
What the vulnerability is
The SAML Single Sign On – SSO Login plugin for WordPress is vulnerable to Authentication Bypass in versions up to, and including, 5.4.6. This is due to the mo_saml_login_validate() ACS handler persisting the X.509 certificate extracted from an incoming SAMLResponse into the mo_saml_required_certificate option before the signature-validation verdict is enforced, because mo_saml_find_certificate() returns false on a fingerprint mismatch rather than halting execution. This makes it possible for unauthenticated attackers to overwrite the plugin's stored IdP signing certificate with an attacker-controlled value, and subsequently forge SAML assertions for any WordPress account — including administrators — to obtain a fully privileged session. Note: The exploit requires the administrator to perform a repair after receiving the test_config_error_wpsamlerr004 error message during the test configuration.
Sources
- https://plugins.trac.wordpress.org/browser/miniorange-saml-20-single-sign-on/tags/5.4.6/class-mo-saml-login-validate.php#L236
- https://plugins.trac.wordpress.org/browser/miniorange-saml-20-single-sign-on/tags/5.4.6/class-mo-saml-login-validate.php#L292
- https://plugins.trac.wordpress.org/browser/miniorange-saml-20-single-sign-on/tags/5.4.6/class-mo-saml-utilities.php#L739
- https://plugins.trac.wordpress.org/browser/miniorange-saml-20-single-sign-on/tags/5.4.6/mo-saml-settings-page.php#L141
- https://www.wordfence.com/threat-intel/vulnerabilities/id/9baea072-2c07-40b6-8410-2ebe752b0874?source=cve