{"id":"CVE-2026-15981","state":"PUBLISHED","title":"SAML Single Sign On <= 5.4.4 - Unauthenticated Authentication Bypass via SAMLResponse Parameter","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.","publishedAt":"2026-07-23T20:33:51.362Z","updatedAt":"2026-07-24T22:06:10.389Z","severity":{"score":9.8,"label":"Critical","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","source":"Wordfence"},"assigner":"Wordfence","products":["cyberlord92 SAML Single Sign On – SSO Login"],"affected":[{"vendor":"cyberlord92","product":"SAML Single Sign On – SSO Login","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThanOrEqual":"5.4.4","versionType":"semver"}]}],"references":["https://www.wordfence.com/threat-intel/vulnerabilities/id/b412f60f-61ea-47b1-a3ef-17275f7951df?source=cve","https://plugins.trac.wordpress.org/browser/miniorange-saml-20-single-sign-on/tags/5.4.4/class-mo-saml-login-validate.php#L118","https://plugins.trac.wordpress.org/browser/miniorange-saml-20-single-sign-on/tags/5.4.4/class-mo-saml-utilities.php#L403","https://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#L938","https://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#L621","https://plugins.trac.wordpress.org/browser/miniorange-saml-20-single-sign-on/tags/5.4.4/class-mo-saml-login-validate.php#L541","https://plugins.trac.wordpress.org/changeset/3611421/miniorange-saml-20-single-sign-on"],"weaknesses":["CWE-287"],"ingestedAt":"2026-10-29T20:11:00.674Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/15xxx/CVE-2026-15981.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-15981","state":"PUBLISHED","datePublished":"2026-07-23T20:33:51.362Z","dateUpdated":"2026-07-24T22:06:10.389Z","assignerShortName":"Wordfence","assignerOrgId":"b15e7b5b-3da4-40ae-a43c-f7aa60e62599","dateReserved":"2026-07-16T16:55:30.527Z"},"containers":{"cna":{"title":"SAML Single Sign On <= 5.4.4 - Unauthenticated Authentication Bypass via SAMLResponse Parameter","descriptions":[{"lang":"en","value":"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. 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