CVE-2026-9263

{
  "id": "CVE-2026-9263",
  "sourceIdentifier": "[email protected]",
  "published": "2026-06-30T17:16:26.387",
  "lastModified": "2026-10-25T21:10:00.770",
  "vulnStatus": "Analyzed",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "The Zephyr Bluetooth controller ISO Adaptation Layer (subsys/bluetooth/controller/ll_sw/isoal.c) fails to validate the length field of a framed ISO PDU start segment. Per the Bluetooth specification a start segment (sc=0) always carries a 3-byte time_offset, so its segment-header len must be at least PDU_ISO_SEG_TIMEOFFSET_SIZE (3). isoal_check_seg_header() accepted start segments with len < 3 as valid, and isoal_rx_framed_consume() then computed length = seg_hdr->len - 3 in a uint8_t, underflowing to 253-255 when len is 0-2. That oversized length is passed to isoal_rx_append_to_sdu(), whose copy is clamped only against the destination SDU buffer size, not the source PDU length, so up to ~255 bytes of controller memory beyond the received PDU are copied (via sink_sdu_write_hci()/net_buf_add_mem) into an HCI ISO data packet and delivered to the host. The PDU and its segment headers are entirely attacker-controlled and arrive over the air, reachable through both the CIS and BIS-sync HCI data paths (hci_driver.c) and the vendor data path (ull_iso.c), so a remote CIS peer or a broadcaster the device is synced to can trigger an out-of-bounds read causing information disclosure to the host and potential denial of service (faults or malformed oversized HCI ISO packets). The flaw affects all Zephyr releases since framed ISO reception was introduced in v3.0.0. The fix rejects sc=0 segments with len < 3 in isoal_check_seg_header() and adds a guard before the subtraction in isoal_rx_framed_consume()."
    },
    {
      "lang": "es",
      "value": "La capa de adaptación ISO del controlador Bluetooth de Zephyr (subsys/bluetooth/controller/ll_sw/isoal.c) no valida el campo de longitud de un segmento de inicio PDU ISO enmarcado. Según la especificación Bluetooth, un segmento de inicio (sc=0) siempre lleva un time_offset de 3 bytes, por lo que la longitud de su encabezado de segmento (len) debe ser al menos PDU_ISO_SEG_TIMEOFFSET_SIZE (3). isoal_check_seg_header() aceptó segmentos de inicio con len < 3 como válidos, e isoal_rx_framed_consume() luego calculó length = seg_hdr  ->  len - 3 en un uint8_t, desbordándose por debajo a 253-255 cuando len es 0-2. Esa longitud sobredimensionada se pasa a isoal_rx_append_to_sdu(), cuya copia se limita solo al tamaño del búfer SDU de destino, no a la longitud de la PDU de origen, por lo que hasta ~255 bytes de memoria del controlador más allá de la PDU recibida se copian (a través de sink_sdu_write_hci()/net_buf_add_mem) en un paquete de datos ISO HCI y se entregan al host. La PDU y sus encabezados de segmento están completamente controlados por el atacante y llegan por aire, accesibles a través de las rutas de datos HCI CIS y BIS-sync (hci_driver.c) y la ruta de datos del proveedor (ull_iso.c), por lo que un par CIS remoto o un emisor al que el dispositivo está sincronizado puede desencadenar una lectura fuera de límites que cause revelación de información al host y una posible denegación de servicio (fallos o paquetes ISO HCI sobredimensionados y malformados). La falla afecta a todas las versiones de Zephyr desde que se introdujo la recepción ISO enmarcada en la v3.0.0. La solución rechaza los segmentos sc=0 con len < 3 en isoal_check_seg_header() y añade una protección antes de la resta en isoal_rx_framed_consume()."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "zephyrproject",
          "product": "zephyr",
          "defaultStatus": "unaffected",
          "collectionURL": "https://github.com/zephyrproject-rtos/zephyr",
          "packageName": "zephyr",
          "programFiles": [
            "subsys/bluetooth/controller/ll_sw/isoal.c"
          ],
          "versions": [
            {
              "version": "3.3.0",
              "lessThan": "4.3.1",
              "versionType": "semver",
              "status": "affected"
            },
            {
              "version": "4.4.0",
              "lessThan": "4.4.1",
              "versionType": "semver",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
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          "baseScore": 6.5,
          "baseSeverity": "MEDIUM",
          "attackVector": "ADJACENT_NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
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  "references": [
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      "url": "https://github.com/zephyrproject-rtos/zephyr/commit/28080d80fc8aca30af1dfd1338bd4481b13c7395",
      "source": "[email protected]",
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