CVE-2026-15981

CVSS Score & Metrics

Base Score

9.8 / 10

Vector String

                                        CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H                                    

Vulnerability 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.

Vulnerability Details

Published Date

July 23, 2026

Last Modified

July 23, 2026

CWE ID

CWE-287

Source

NVD

Vendor

cyberlord92

Product

SAML Single Sign On – SSO Login

CVSS Score & Metrics

Vulnerability Description

Vulnerability Details

External References

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