FKIE_CVE-2026-4406

Vulnerability from fkie_nvd - Published: 2026-04-08 00:16 - Updated: 2026-04-08 21:26
Summary
The Gravity Forms plugin for WordPress is vulnerable to Reflected Cross-Site Scripting via the `form_ids` parameter in the `gform_get_config` AJAX action in all versions up to, and including, 2.9.30. This is due to the `GFCommon::send_json()` method outputting JSON-encoded data wrapped in HTML comment delimiters using `echo` and `wp_die()`, which serves the response with a `Content-Type: text/html` header instead of `application/json`. The `wp_json_encode()` function does not HTML-encode angle brackets within JSON string values, allowing injected HTML/script tags in `form_ids` array values to be parsed and executed by the browser. The required `config_nonce` is generated with `wp_create_nonce('gform_config_ajax')` and is publicly embedded on every page that renders a Gravity Forms form, making it identical for all unauthenticated visitors within the same 12-hour nonce tick. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that execute if they can successfully trick a user into performing an action such as clicking on a link. This vulnerability cannot be exploited against users who are authenticated on the target system, but could be used to alter the target page.
Impacted products
Vendor Product Version

{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "The Gravity Forms plugin for WordPress is vulnerable to Reflected Cross-Site Scripting via the `form_ids` parameter in the `gform_get_config` AJAX action in all versions up to, and including, 2.9.30. This is due to the `GFCommon::send_json()` method outputting JSON-encoded data wrapped in HTML comment delimiters using `echo` and `wp_die()`, which serves the response with a `Content-Type: text/html` header instead of `application/json`. The `wp_json_encode()` function does not HTML-encode angle brackets within JSON string values, allowing injected HTML/script tags in `form_ids` array values to be parsed and executed by the browser. The required `config_nonce` is generated with `wp_create_nonce(\u0027gform_config_ajax\u0027)` and is publicly embedded on every page that renders a Gravity Forms form, making it identical for all unauthenticated visitors within the same 12-hour nonce tick. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that execute if they can successfully trick a user into performing an action such as clicking on a link. This vulnerability cannot be exploited against users who are authenticated on the target system, but could be used to alter the target page."
    }
  ],
  "id": "CVE-2026-4406",
  "lastModified": "2026-04-08T21:26:35.910",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "HIGH",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 4.7,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "LOW",
          "integrityImpact": "LOW",
          "privilegesRequired": "NONE",
          "scope": "CHANGED",
          "userInteraction": "REQUIRED",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 1.6,
        "impactScore": 2.7,
        "source": "security@wordfence.com",
        "type": "Primary"
      }
    ]
  },
  "published": "2026-04-08T00:16:05.490",
  "references": [
    {
      "source": "security@wordfence.com",
      "url": "https://docs.gravityforms.com/gravityforms-change-log/"
    },
    {
      "source": "security@wordfence.com",
      "url": "https://plugins.trac.wordpress.org/browser/gravityforms/trunk/common.php#L8267"
    },
    {
      "source": "security@wordfence.com",
      "url": "https://plugins.trac.wordpress.org/browser/gravityforms/trunk/includes/config/class-gf-config-collection.php#L56"
    },
    {
      "source": "security@wordfence.com",
      "url": "https://plugins.trac.wordpress.org/browser/gravityforms/trunk/includes/config/class-gf-config-service-provider.php#L144"
    },
    {
      "source": "security@wordfence.com",
      "url": "https://plugins.trac.wordpress.org/browser/gravityforms/trunk/includes/config/items/class-gf-config-global.php#L22"
    },
    {
      "source": "security@wordfence.com",
      "url": "https://www.wordfence.com/threat-intel/vulnerabilities/id/4126d452-65a9-48f5-a3f5-5be1b8fff80c?source=cve"
    }
  ],
  "sourceIdentifier": "security@wordfence.com",
  "vulnStatus": "Awaiting Analysis",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-79"
        }
      ],
      "source": "security@wordfence.com",
      "type": "Primary"
    }
  ]
}


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  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
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  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


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