CVE-2026-11368

{
  "id": "CVE-2026-11368",
  "sourceIdentifier": "[email protected]",
  "published": "2026-08-04T15:16:24.843",
  "lastModified": "2026-10-23T23:10:00.157",
  "vulnStatus": "Analyzed",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "The Bluetooth host ATT layer (subsys/bluetooth/host/att.c) associates each in-flight ATT TX buffer with its owning channel via the static tx_meta_data_storage[] array (data->att_chan = chan). When a buffer's last reference is dropped, its net-buf destroy callback defers the completion handling to the system workqueue (att_tx_destroy -> att_tx_destroy_work_handler -> att_on_sent_cb -> bt_att_sent), where bt_att_sent dereferences the channel and its ATT context (sys_slist_get(&att->reqs)).\n\nWhen a peer disconnects while an ATT PDU (a server notification/indication or any response) is still in flight in the controller TX path, L2CAP tears the channel down in l2cap_chan_del(): it runs the disconnected callback and then the released callback (bt_att_released), which frees the channel slab slot. Because the in-flight buffer is held by the connection TX path rather than the channel's own queue, its deferred destroy work can run after the channel has been freed. The att_on_sent_cb guard intended to drop the stale callback itself dereferences meta->att_chan, which is now a dangling pointer into a freed (and possibly reused) slab slot.\n\nA remote peer with an ATT connection can drive this by disconnecting during routine ATT traffic; no pairing or user interaction is required to reach the ATT bearer. The result is a use-after-free read/write of freed channel memory, reliably crashing the Bluetooth host (denial of service) and, because the channel slab slot may be reused, potentially corrupting live memory.\n\nThe fix makes bt_att_released() NULL the att_chan field of every tx_meta_data_storage[] entry still referencing the channel before freeing it, so the deferred guard observes a NULL pointer and drops the callback. Teardown and the destroy work both run on the cooperative system workqueue, so the array update is serialized and needs no lock."
    },
    {
      "lang": "es",
      "value": "La capa ATT del host Bluetooth (subsys/bluetooth/host/att.c) asocia cada búfer ATT TX en tránsito con su canal propietario a través del array estático tx_meta_data_storage[] (data  ->  att_chan = chan). Cuando se elimina la última referencia de un búfer, su callback de destrucción net-buf aplaza el manejo de la finalización a la cola de trabajo del sistema (att_tx_destroy   ->   att_tx_destroy_work_handler   ->   att_on_sent_cb   ->   bt_att_sent), donde bt_att_sent desreferencia el canal y su contexto ATT (sys_slist_get(&att  ->  reqs)).\n\nCuando un par se desconecta mientras una PDU ATT (una notificación/indicación del servidor o cualquier respuesta) todavía está en tránsito en la ruta TX del controlador, L2CAP cierra el canal en l2cap_chan_del(): ejecuta el callback de desconexión y luego el callback de liberación (bt_att_released), que libera el slot de slab del canal. Debido a que el búfer en tránsito es retenido por la ruta TX de la conexión en lugar de la propia cola del canal, su trabajo de destrucción aplazado puede ejecutarse después de que el canal haya sido liberado. El guard att_on_sent_cb, destinado a descartar el callback obsoleto, desreferencia meta  ->  att_chan, que ahora es un puntero colgante a un slot de slab liberado (y posiblemente reutilizado).\n\nUn par remoto con una conexión ATT puede provocar esto desconectándose durante el tráfico ATT rutinario; no se requiere emparejamiento ni interacción del usuario para alcanzar el portador ATT. El resultado es un uso después de liberación de lectura/escritura de memoria de canal liberada, provocando el bloqueo fiable del host Bluetooth (denegación de servicio) y, debido a que el slot de slab del canal puede ser reutilizado, potencialmente corrompiendo la memoria activa.\n\nLa solución hace que bt_att_released() anule el campo att_chan de cada entrada de tx_meta_data_storage[] que aún referencia el canal antes de liberarlo, para que el guard aplazado observe un puntero NULL y descarte el callback. Tanto el desmantelamiento como el trabajo de destrucción se ejecutan en la cola de trabajo cooperativa del sistema, por lo que la actualización del array está serializada y no necesita bloqueo."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "zephyrproject",
          "product": "zephyr",
          "defaultStatus": "unaffected",
          "collectionURL": "https://github.com/zephyrproject-rtos/zephyr",
          "packageName": "zephyr",
          "programFiles": [
            "subsys/bluetooth/host/att.c"
          ],
          "versions": [
            {
              "version": "4.4.0",
              "lessThan": "4.4.2",
              "versionType": "semver",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
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          "baseScore": 7.1,
          "baseSeverity": "HIGH",
          "attackVector": "ADJACENT_NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "NONE",
          "integrityImpact": "LOW",
          "availabilityImpact": "HIGH"
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        "type": "Primary",
        "cvssData": {
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          "attackVector": "ADJACENT_NETWORK",
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          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
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    "ssvcV203": [
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        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-08-04T17:56:36.608577Z",
          "id": "CVE-2026-11368",
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          "role": "CISA Coordinator",
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  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-416"
        }
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  "configurations": [
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          "cpeMatch": [
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  "references": [
    {
      "url": "https://github.com/zephyrproject-rtos/zephyr/commit/dfdea9bad8d9b5b31c125e97fcffb549f2217caa",
      "source": "[email protected]",
      "tags": [
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    {
      "url": "https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-85vg-gwc4-77g7",
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}