CVE-2026-15981
published 2026-07-23CVE-2026-15981: 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…
PriorityP186critical9.8CVSS 3.1
AVNACLPRNUINSUCHIHAH
ITWEXPLOITVulnCheck KEVInitial access
Exploited in the wild
EPSS
0.81%
54.6th percentile
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.
Affected
1 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| cyberlord92 | saml_single_sign_on_sso_login | <= 5.4.4 | — |
CVSS provenance
nvdv3.19.8CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
vulncheck9.8CRITICAL
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VulDB
cyberlord92 SAML Single Sign On Plugin up to 5.4.4 on WordPress mo_saml_validate_signature signature verification
vuldb·2026-07-23·CVSS 9.8
CVE-2026-15981 [CRITICAL] cyberlord92 SAML Single Sign On Plugin up to 5.4.4 on WordPress mo_saml_validate_signature signature verification
A vulnerability was found in cyberlord92 SAML Single Sign On Plugin up to 5.4.4 on WordPress and classified as critical. The affected element is the function mo_saml_validate_signature. The manipulation results in improper verification of cryptographic signature.
This vulnerability is identified as CVE-2026-15981. The attack can be executed remotely. There is not any exploit available.
GHSA
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.
ghsa_unreviewed·2026-07-23
CVE-2026-15981 [CRITICAL] CWE-287 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.
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 t
VulnCheck
miniorange saml_sp_single_sign_on Improper Authentication
vulncheck·2026·CVSS 9.8
CVE-2026-15981 [CRITICAL] miniorange saml_sp_single_sign_on Improper Authentication
miniorange saml_sp_single_sign_on Improper Authentication
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 a
No detection rules found.
No public exploits indexed.
https://plugins.trac.wordpress.org/browser/miniorange-saml-20-single-sign-on/tags/5.4.4/class-mo-saml-login-validate.php#L118https://plugins.trac.wordpress.org/browser/miniorange-saml-20-single-sign-on/tags/5.4.4/class-mo-saml-login-validate.php#L541https://plugins.trac.wordpress.org/browser/miniorange-saml-20-single-sign-on/tags/5.4.4/class-mo-saml-utilities.php#L403https://plugins.trac.wordpress.org/browser/miniorange-saml-20-single-sign-on/tags/5.4.4/includes/lib/SAML2Core/class-mo-saml-xml-security-dsig.php#L938https://plugins.trac.wordpress.org/browser/miniorange-saml-20-single-sign-on/tags/5.4.4/includes/lib/SAML2Core/class-mo-saml-xml-security-key.php#L621https://plugins.trac.wordpress.org/changeset/3611421/miniorange-saml-20-single-sign-onhttps://www.wordfence.com/threat-intel/vulnerabilities/id/b412f60f-61ea-47b1-a3ef-17275f7951df?source=cve
2026-07-23
Published
Exploited in the wild