SAML Single Sign On <= 5.4.6 - Unauthenticated Authentication Bypass via X.509 Certificate Poisoning

{
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "cveMetadata": {
    "cveId": "CVE-2026-75807",
    "assignerOrgId": "b15e7b5b-3da4-40ae-a43c-f7aa60e62599",
    "assignerShortName": "Wordfence",
    "dateUpdated": "2026-08-29T17:25:48.408Z",
    "dateReserved": "2026-08-18T09:38:56.449Z",
    "datePublished": "2026-08-29T17:25:48.408Z",
    "state": "PUBLISHED"
  },
  "containers": {
    "cna": {
      "providerMetadata": {
        "orgId": "b15e7b5b-3da4-40ae-a43c-f7aa60e62599",
        "shortName": "Wordfence",
        "dateUpdated": "2026-08-29T17:25:48.408Z"
      },
      "title": "SAML Single Sign On <= 5.4.6 - Unauthenticated Authentication Bypass via X.509 Certificate Poisoning",
      "descriptions": [
        {
          "lang": "en",
          "value": "The SAML Single Sign On – SSO Login plugin for WordPress is vulnerable to Authentication Bypass in versions up to, and including, 5.4.6. This is due to the mo_saml_login_validate() ACS handler persisting the X.509 certificate extracted from an incoming SAMLResponse into the mo_saml_required_certificate option before the signature-validation verdict is enforced, because mo_saml_find_certificate() returns false on a fingerprint mismatch rather than halting execution. This makes it possible for unauthenticated attackers to overwrite the plugin's stored IdP signing certificate with an attacker-controlled value, and subsequently forge SAML assertions for any WordPress account — including administrators — to obtain a fully privileged session. Note: The exploit requires the administrator to perform a repair after receiving the test_config_error_wpsamlerr004 error message during the test configuration."
        }
      ],
      "affected": [
        {
          "vendor": "cyberlord92",
          "product": "SAML Single Sign On – SSO Login",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "0",
              "status": "affected",
              "versionType": "semver",
              "lessThanOrEqual": "5.4.6"
            }
          ]
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "lang": "en",
              "description": "CWE-287 Improper Authentication",
              "cweId": "CWE-287",
              "type": "CWE"
            }
          ]
        }
      ],
      "references": [
        {
          "url": "https://www.wordfence.com/threat-intel/vulnerabilities/id/9baea072-2c07-40b6-8410-2ebe752b0874?source=cve"
        },
        {
          "url": "https://plugins.trac.wordpress.org/browser/miniorange-saml-20-single-sign-on/tags/5.4.6/class-mo-saml-login-validate.php#L236"
        },
        {
          "url": "https://plugins.trac.wordpress.org/browser/miniorange-saml-20-single-sign-on/tags/5.4.6/class-mo-saml-login-validate.php#L292"
        },
        {
          "url": "https://plugins.trac.wordpress.org/browser/miniorange-saml-20-single-sign-on/tags/5.4.6/class-mo-saml-utilities.php#L739"
        },
        {
          "url": "https://plugins.trac.wordpress.org/browser/miniorange-saml-20-single-sign-on/tags/5.4.6/mo-saml-settings-page.php#L141"
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "version": "3.1",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H",
            "baseScore": 7.5,
            "baseSeverity": "HIGH"
          }
        }
      ],
      "timeline": [
        {
          "time": "2026-08-18T09:55:16.000Z",
          "lang": "en",
          "value": "Vendor Notified"
        },
        {
          "time": "2026-08-29T05:01:46.000Z",
          "lang": "en",
          "value": "Disclosed"
        }
      ],
      "credits": [
        {
          "lang": "en",
          "value": "Tanishq Shah",
          "type": "finder"
        },
        {
          "lang": "en",
          "value": "Thatchapol Booranatanit (AliceZz)",
          "type": "finder"
        }
      ]
    }
  }
}