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CVE-2026-15981 Detail

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.


Metrics

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CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

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URL Source(s) Tag(s)
Wordfence
Wordfence
Wordfence
Wordfence
Wordfence
Wordfence
Wordfence

Weakness Enumeration

CWE-ID CWE Name Source
CWE-287 Improper Authentication Wordfence  

Change History

1 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2026-15981
NVD Published Date:
07/23/2026
NVD Last Modified:
07/23/2026
Source:
Wordfence