GHSA-WGJX-Q85H-87V2

Vulnerability from github – Published: 2026-07-23 21:31 – Updated: 2026-07-23 21:31
VLAI
Details

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.

Severity
9.8 (Critical)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
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{
  "affected": [],
  "aliases": [
    "CVE-2026-15981"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-287"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-07-23T21:17:03Z",
    "severity": "CRITICAL"
  },
  "details": "The SAML Single Sign On \u2013 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\u0027s 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 \u2014 bypassing verification entirely and resulting in wp_set_auth_cookie() being called for the targeted account.",
  "id": "GHSA-wgjx-q85h-87v2",
  "modified": "2026-07-23T21:31:02Z",
  "published": "2026-07-23T21:31:02Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-15981"
    },
    {
      "type": "WEB",
      "url": "https://plugins.trac.wordpress.org/browser/miniorange-saml-20-single-sign-on/tags/5.4.4/class-mo-saml-login-validate.php#L118"
    },
    {
      "type": "WEB",
      "url": "https://plugins.trac.wordpress.org/browser/miniorange-saml-20-single-sign-on/tags/5.4.4/class-mo-saml-login-validate.php#L541"
    },
    {
      "type": "WEB",
      "url": "https://plugins.trac.wordpress.org/browser/miniorange-saml-20-single-sign-on/tags/5.4.4/class-mo-saml-utilities.php#L403"
    },
    {
      "type": "WEB",
      "url": "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"
    },
    {
      "type": "WEB",
      "url": "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"
    },
    {
      "type": "WEB",
      "url": "https://plugins.trac.wordpress.org/changeset/3611421/miniorange-saml-20-single-sign-on"
    },
    {
      "type": "WEB",
      "url": "https://www.wordfence.com/threat-intel/vulnerabilities/id/b412f60f-61ea-47b1-a3ef-17275f7951df?source=cve"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}



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