FKIE_CVE-2026-6394

Vulnerability from fkie_nvd - Published: 2026-05-20 02:16 - Updated: 2026-07-24 08:10
Severity
5.4 (Medium) - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N
Summary
The Nexa Blocks – Gutenberg Blocks, Page Builder for Gutenberg Editor & FSE plugin for WordPress is vulnerable to Server-Side Request Forgery (SSRF) in versions up to and including 1.1.1. This is due to the import_demo() function accepting a user-supplied URL in the demo_json_file POST parameter and passing it directly to wp_remote_get() without any URL validation or restriction against internal or private network destinations. The nexa_blocks_nonce required for the AJAX action is publicly exposed in the HTML source of any frontend page where the plugin is active via wp_localize_script on the enqueue_block_assets hook, effectively making the nonce available to all visitors and bypassing any intended authentication barrier. This makes it possible for unauthenticated attackers to make server-side HTTP requests to arbitrary internal or external destinations, potentially exposing internal services, cloud metadata endpoints such as the AWS instance metadata service, localhost services, and other resources not intended to be publicly accessible. A secondary SSRF vector also exists whereby image URLs extracted from the attacker-controlled JSON response are subsequently fetched via a second wp_remote_get() call, allowing chained exploitation through a crafted JSON payload.
References
security@wordfence.comhttps://plugins.trac.wordpress.org/browser/nexa-blocks/tags/1.1.1/inc/classes/enqueue-assets.php#L84
security@wordfence.comhttps://plugins.trac.wordpress.org/browser/nexa-blocks/tags/1.1.1/inc/template/template.php#L236
security@wordfence.comhttps://plugins.trac.wordpress.org/browser/nexa-blocks/tags/1.1.1/inc/template/template.php#L242
security@wordfence.comhttps://plugins.trac.wordpress.org/browser/nexa-blocks/trunk/inc/classes/enqueue-assets.php#L84
security@wordfence.comhttps://plugins.trac.wordpress.org/browser/nexa-blocks/trunk/inc/template/template.php#L236
security@wordfence.comhttps://plugins.trac.wordpress.org/browser/nexa-blocks/trunk/inc/template/template.php#L242
security@wordfence.comhttps://www.wordfence.com/threat-intel/vulnerabilities/id/b4bb3067-7953-466d-a469-8a101450f133?source=cve
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Nexa Blocks \u2013 Gutenberg Blocks, Page Builder for Gutenberg Editor \u0026 FSE",
          "vendor": "wpdive",
          "versions": [
            {
              "lessThanOrEqual": "1.1.1",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "source": "security@wordfence.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "The Nexa Blocks \u2013 Gutenberg Blocks, Page Builder for Gutenberg Editor \u0026 FSE plugin for WordPress is vulnerable to Server-Side Request Forgery (SSRF) in versions up to and including 1.1.1. This is due to the import_demo() function accepting a user-supplied URL in the demo_json_file POST parameter and passing it directly to wp_remote_get() without any URL validation or restriction against internal or private network destinations. The nexa_blocks_nonce required for the AJAX action is publicly exposed in the HTML source of any frontend page where the plugin is active via wp_localize_script on the enqueue_block_assets hook, effectively making the nonce available to all visitors and bypassing any intended authentication barrier. This makes it possible for unauthenticated attackers to make server-side HTTP requests to arbitrary internal or external destinations, potentially exposing internal services, cloud metadata endpoints such as the AWS instance metadata service, localhost services, and other resources not intended to be publicly accessible. A secondary SSRF vector also exists whereby image URLs extracted from the attacker-controlled JSON response are subsequently fetched via a second wp_remote_get() call, allowing chained exploitation through a crafted JSON payload."
    },
    {
      "lang": "es",
      "value": "El plugin Nexa Blocks - Gutenberg Blocks, Page Builder for Gutenberg Editor \u0026 FSE para WordPress es vulnerable a falsificaci\u00f3n de petici\u00f3n del lado del servidor (SSRF) en versiones hasta la 1.1.1 inclusive. Esto se debe a que la funci\u00f3n import_demo() acepta una URL proporcionada por el usuario en el par\u00e1metro POST demo_json_file y la pasa directamente a wp_remote_get() sin ninguna validaci\u00f3n de URL o restricci\u00f3n contra destinos de red internos o privados. El nexa_blocks_nonce requerido para la acci\u00f3n AJAX est\u00e1 expuesto p\u00fablicamente en el c\u00f3digo fuente HTML de cualquier p\u00e1gina de frontend donde el plugin est\u00e1 activo a trav\u00e9s de wp_localize_script en el hook enqueue_block_assets, haciendo que el nonce est\u00e9 efectivamente disponible para todos los visitantes y eludiendo cualquier barrera de autenticaci\u00f3n prevista. Esto permite a atacantes no autenticados realizar peticiones HTTP del lado del servidor a destinos internos o externos arbitrarios, exponiendo potencialmente servicios internos, puntos finales de metadatos en la nube como el servicio de metadatos de instancia de AWS, servicios de localhost y otros recursos no destinados a ser accesibles p\u00fablicamente. Tambi\u00e9n existe un vector SSRF secundario por el cual las URL de im\u00e1genes extra\u00eddas de la respuesta JSON controlada por el atacante son posteriormente obtenidas a trav\u00e9s de una segunda llamada a wp_remote_get(), permitiendo la explotaci\u00f3n encadenada a trav\u00e9s de una carga \u00fatil JSON manipulada."
    }
  ],
  "id": "CVE-2026-6394",
  "lastModified": "2026-07-24T08:10:00.150",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "HIGH",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 5.4,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "LOW",
          "integrityImpact": "LOW",
          "privilegesRequired": "NONE",
          "scope": "CHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 2.2,
        "impactScore": 2.7,
        "source": "security@wordfence.com",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-6394",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-05-20T13:51:10.698992Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-05-20T02:16:37.490",
  "references": [
    {
      "source": "security@wordfence.com",
      "url": "https://plugins.trac.wordpress.org/browser/nexa-blocks/tags/1.1.1/inc/classes/enqueue-assets.php#L84"
    },
    {
      "source": "security@wordfence.com",
      "url": "https://plugins.trac.wordpress.org/browser/nexa-blocks/tags/1.1.1/inc/template/template.php#L236"
    },
    {
      "source": "security@wordfence.com",
      "url": "https://plugins.trac.wordpress.org/browser/nexa-blocks/tags/1.1.1/inc/template/template.php#L242"
    },
    {
      "source": "security@wordfence.com",
      "url": "https://plugins.trac.wordpress.org/browser/nexa-blocks/trunk/inc/classes/enqueue-assets.php#L84"
    },
    {
      "source": "security@wordfence.com",
      "url": "https://plugins.trac.wordpress.org/browser/nexa-blocks/trunk/inc/template/template.php#L236"
    },
    {
      "source": "security@wordfence.com",
      "url": "https://plugins.trac.wordpress.org/browser/nexa-blocks/trunk/inc/template/template.php#L242"
    },
    {
      "source": "security@wordfence.com",
      "url": "https://www.wordfence.com/threat-intel/vulnerabilities/id/b4bb3067-7953-466d-a469-8a101450f133?source=cve"
    }
  ],
  "sourceIdentifier": "security@wordfence.com",
  "vulnStatus": "Deferred",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-918"
        }
      ],
      "source": "security@wordfence.com",
      "type": "Secondary"
    }
  ]
}



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