cve-2026-15981
HIGH vulncheck_kevThe 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.
- Published
- 2026-08-21 00:00 UTC
- Last Modified
- 2026-08-21
CVSS details not available.
No product information available.
No references available.
No linked vulnerabilities found.
{
"cvss": 0.0,
"datePublished": "2026-08-21T00:00:00Z",
"dateUpdated": "2026-08-21T00:00:00Z",
"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.",
"dueDate": "",
"id": "CVE-2026-15981",
"kev_catalogs": [
"vulncheck"
],
"knownRansomwareCampaignUse": "Unknown",
"product": "saml_sp_single_sign_on",
"requiredAction": "Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.",
"severity": "HIGH",
"source": "vulncheck_kev",
"title": "MiniOrange saml_sp_single_sign_on Improper Authentication",
"vendor": "MiniOrange"
}