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 mo_saml_validate_signature() function performing a loose boolean check on the raw tri-state integer returned by PHP's openssl_verify(), causing an error return value of -1 to be evaluated as truthy and therefore treated as a successful signature verification. This makes it possible for unauthenticated attackers to log in as any existing WordPress user, including administrators, by submitting a crafted SAMLResponse containing an attacker-controlled NameID and a deliberately malformed signature value that triggers an OpenSSL processing error — bypassing verification entirely and resulting in wp_set_auth_cookie() being called for the targeted account.
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Affected Vendors & Products
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History
Mon, 27 Jul 2026 15:45:00 +0000
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Cyberlord92
Cyberlord92 oauth Single Sign On – Sso (oauth Client) Wordpress Wordpress wordpress |
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Cyberlord92
Cyberlord92 oauth Single Sign On – Sso (oauth Client) Wordpress Wordpress wordpress |
Fri, 24 Jul 2026 22:30:00 +0000
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ssvc
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Thu, 23 Jul 2026 21:45:00 +0000
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| Description | 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 mo_saml_validate_signature() function performing a loose boolean check on the raw tri-state integer returned by PHP's openssl_verify(), causing an error return value of -1 to be evaluated as truthy and therefore treated as a successful signature verification. This makes it possible for unauthenticated attackers to log in as any existing WordPress user, including administrators, by submitting a crafted SAMLResponse containing an attacker-controlled NameID and a deliberately malformed signature value that triggers an OpenSSL processing error — bypassing verification entirely and resulting in wp_set_auth_cookie() being called for the targeted account. | |
| Title | SAML Single Sign On <= 5.4.4 - Unauthenticated Authentication Bypass via SAMLResponse Parameter | |
| Weaknesses | CWE-287 | |
| References |
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| Metrics |
cvssV3_1
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Status: PUBLISHED
Assigner: Wordfence
Published: 2026-07-23T20:33:51.362Z
Updated: 2026-07-24T22:06:10.389Z
Reserved: 2026-07-16T16:55:30.527Z
Link: CVE-2026-15981
Updated: 2026-07-24T22:06:03.900Z
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