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CVE-2026-11810

Full vulnerability record from the local CVENow database.

Description

The UpdateHub firmware-update agent's probe handler (z_impl_updatehub_probe() in subsys/mgmt/updatehub/updatehub.c) parses the JSON metadata returned by the update server into a fixed two-level nested-array struct. After parsing it validates only the outer array length (objects_len != 2) and then dereferences objects[1].objects[0].objects.sha256sum via strlen() without checking that the inner object array of element [1] is non-empty. The metadata is attacker-influenceable network input: the agent fetches it over CoAP from the configured UpdateHub server during its routine OTA probe. A malicious or compromised update server (or, when DTLS is disabled, a network man-in-the-middle) can return a response whose second outer object array is empty. Because the parse target is zero-initialised, the corresponding objects[1].objects[0].objects.sha256sum pointer is NULL, and the subsequent strlen() dereferences address zero. The same defect exists in both the 'any boards' and 'some boards' metadata layouts. The resulting CPU fault is fatal under Zephyr's default error handling, halting or resetting the device, so the flaw is a remotely triggerable denial of service. Impact is limited to availability; it is a read from NULL with no out-of-bounds write, memory corruption, or information disclosure. The fix rejects metadata whose inner object array is empty before any dereference, on both layouts.

Severity
HIGH
CVSS score
7.5 (v3.1)
Vulnerability status
Awaiting Analysis
Source identifier
Published
2026-08-10 21:17:19.223000
Last modified
2026-10-23 19:10:00.167000
View original CVE JSON
{
  "id": "CVE-2026-11810",
  "sourceIdentifier": "[email protected]",
  "published": "2026-08-10T21:17:19.223",
  "lastModified": "2026-10-23T19:10:00.167",
  "vulnStatus": "Awaiting Analysis",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "The UpdateHub firmware-update agent's probe handler (z_impl_updatehub_probe() in subsys/mgmt/updatehub/updatehub.c) parses the JSON metadata returned by the update server into a fixed two-level nested-array struct. After parsing it validates only the outer array length (objects_len != 2) and then dereferences objects[1].objects[0].objects.sha256sum via strlen() without checking that the inner object array of element [1] is non-empty.\n\nThe metadata is attacker-influenceable network input: the agent fetches it over CoAP from the configured UpdateHub server during its routine OTA probe. A malicious or compromised update server (or, when DTLS is disabled, a network man-in-the-middle) can return a response whose second outer object array is empty. Because the parse target is zero-initialised, the corresponding objects[1].objects[0].objects.sha256sum pointer is NULL, and the subsequent strlen() dereferences address zero. The same defect exists in both the 'any boards' and 'some boards' metadata layouts.\n\nThe resulting CPU fault is fatal under Zephyr's default error handling, halting or resetting the device, so the flaw is a remotely triggerable denial of service. Impact is limited to availability; it is a read from NULL with no out-of-bounds write, memory corruption, or information disclosure. The fix rejects metadata whose inner object array is empty before any dereference, on both layouts."
    },
    {
      "lang": "es",
      "value": "El gestor de sondeo del agente de actualización de firmware de UpdateHub (z_impl_updatehub_probe() en subsys/mgmt/updatehub/updatehub.c) analiza los metadatos JSON devueltos por el servidor de actualizaciones en una estructura de array anidado de dos niveles fija. Después de analizarlos, valida solo la longitud del array externo (objects_len != 2) y luego desreferencia objects[1].objects[0].objects.sha256sum a través de strlen() sin comprobar que el array de objetos interno del elemento [1] no está vacío.\n\nLos metadatos son una entrada de red influenciable por el atacante: el agente los obtiene a través de CoAP del servidor UpdateHub configurado durante su sondeo OTA rutinario. Un servidor de actualizaciones malicioso o comprometido (o, cuando DTLS está deshabilitado, un man-in-the-middle de red) puede devolver una respuesta cuyo segundo array de objetos externo está vacío. Debido a que el objetivo de análisis se inicializa a cero, el puntero objects[1].objects[0].objects.sha256sum correspondiente es NULL, y la strlen() subsiguiente desreferencia la dirección cero. El mismo defecto existe tanto en los diseños de metadatos ’any boards’ como ’some boards’.\n\nLa falla de CPU resultante es fatal bajo el manejo de errores predeterminado de Zephyr, deteniendo o reiniciando el dispositivo, por lo que la falla es una denegación de servicio que puede ser activada remotamente. El impacto se limita a la disponibilidad; es una lectura desde NULL sin escritura fuera de límites, corrupción de memoria o revelación de información. La solución rechaza los metadatos cuyo array de objetos interno está vacío antes de cualquier desreferencia, en ambos diseños."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "zephyrproject",
          "product": "zephyr",
          "defaultStatus": "unaffected",
          "collectionURL": "https://github.com/zephyrproject-rtos/zephyr",
          "packageName": "zephyr",
          "programFiles": [
            "subsys/mgmt/updatehub/updatehub.c"
          ],
          "versions": [
            {
              "version": "3.7.0",
              "lessThan": "4.4.2",
              "versionType": "semver",
              "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:N/I:N/A:H",
          "baseScore": 7.5,
          "baseSeverity": "HIGH",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 3.6
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-08-11T14:32:27.987817Z",
          "id": "CVE-2026-11810",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-476"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://github.com/zephyrproject-rtos/zephyr/commit/3424082022cb39d568434021b1d6f68b6a7fb3bf",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-jfpc-324j-84ww",
      "source": "[email protected]"
    }
  ]
}