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.
History

Mon, 31 Aug 2026 21:30:00 +0000

Type Values Removed Values Added
First Time appeared Cyberlord92
Cyberlord92 oauth Single Sign On – Sso (oauth Client)
Wordpress
Wordpress wordpress
Vendors & Products Cyberlord92
Cyberlord92 oauth Single Sign On – Sso (oauth Client)
Wordpress
Wordpress wordpress

Mon, 31 Aug 2026 19:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Sat, 29 Aug 2026 17:30:00 +0000

Type Values Removed Values Added
Description 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.
Title SAML Single Sign On <= 5.4.6 - Unauthenticated Authentication Bypass via X.509 Certificate Poisoning
Weaknesses CWE-287
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H'}


cve-icon MITRE

Status: PUBLISHED

Assigner: Wordfence

Published: 2026-08-29T17:25:48.408Z

Updated: 2026-08-31T18:10:18.791Z

Reserved: 2026-08-18T09:38:56.449Z

Link: CVE-2026-75807

cve-icon Vulnrichment

Updated: 2026-08-31T18:10:13.233Z

cve-icon NVD

Status : Deferred

Published: 2026-08-29T18:16:36.313

Modified: 2026-08-31T20:14:36.250

Link: CVE-2026-75807

cve-icon Redhat

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