CVE-2026-42854

{
  "id": "CVE-2026-42854",
  "sourceIdentifier": "[email protected]",
  "published": "2026-05-12T22:16:34.930",
  "lastModified": "2026-10-26T14:10:00.130",
  "vulnStatus": "Analyzed",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "arduino-esp32 is an Arduino core for the ESP32, ESP32-S2, ESP32-S3, ESP32-C3, ESP32-C6 and ESP32-H2 microcontrollers. Prior to 3.3.8, the WebServer multipart form parser in arduino-esp32 allocates a Variable Length Array (VLA) on the stack whose size is derived from an attacker-controlled HTTP header field (Content-Type: multipart/form-data; boundary=...) without enforcing any length limit. Sending a boundary string longer than ~8000 characters overflows the 8192-byte task stack of the loopTask, causing a crash and potential remote code execution. This vulnerability is fixed in 3.3.8."
    },
    {
      "lang": "es",
      "value": "arduino-esp32 es un core de Arduino para los microcontroladores ESP32, ESP32-S2, ESP32-S3, ESP32-C3, ESP32-C6 y ESP32-H2. Antes de la versión 3.3.8, el analizador de formularios multipart WebServer en arduino-esp32 asigna un Array de Longitud Variable (VLA) en la pila cuyo tamaño se deriva de un campo de encabezado HTTP controlado por un atacante (Content-Type: multipart/form-data; boundary=...) sin aplicar ningún límite de longitud. Enviar una cadena de límite de más de ~8000 caracteres desborda la pila de tareas de 8192 bytes de loopTask, causando un fallo y una potencial ejecución remota de código. Esta vulnerabilidad se corrige en la versión 3.3.8."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "espressif",
          "product": "arduino-esp32",
          "versions": [
            {
              "version": "< 3.3.8",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "[email protected]",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "baseScore": 9.8,
          "baseSeverity": "CRITICAL",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 5.9
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-05-13T14:24:33.796662Z",
          "id": "CVE-2026-42854",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-121"
        }
      ]
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "operator": "OR",
          "negate": false,
          "cpeMatch": [
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:a:espressif:arduino-esp32:*:-:*:*:*:*:*:*",
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              "matchCriteriaId": "308785AC-A885-47B5-9131-64AE662B6525"
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  "references": [
    {
      "url": "https://github.com/espressif/arduino-esp32/security/advisories/GHSA-8cmm-3887-r32j",
      "source": "[email protected]",
      "tags": [
        "Exploit",
        "Vendor Advisory"
      ]
    },
    {
      "url": "https://github.com/espressif/arduino-esp32/security/advisories/GHSA-8cmm-3887-r32j",
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
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}