PT-2026-64168 · Cyberlord92 · Saml Single Sign On – Sso Login

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CVE-2026-15981

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Published

2026-07-23

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Updated

2026-07-23

CVSS v3.1

9.8

Critical

VectorAV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
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.

Fix

Improper Authentication

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Weakness Enumeration

Related Identifiers

CVE-2026-15981

Affected Products

Saml Single Sign On – Sso Login