CVE-2026-63944

Estado: Pendiente de análisisAlta (8.8)—

In the Linux kernel, the following vulnerability has been resolved:

Bluetooth: hci_sync: fix UAF in hci_le_create_cis_sync

hci_le_create_cis_sync() dereferences conn->conn_timeout after releasing both rcu_read_lock() and hci_dev_lock(hdev). The conn pointer was obtained from an RCU-protected iteration over hdev->conn_hash.list and is not valid once these locks are dropped. A concurrent disconnect can free the hci_conn between the unlock and the dereference, causing a use-after-free read.

The cancellation mechanism in hci_conn_del() cannot prevent this because hci_le_create_cis_pending() queues hci_create_cis_sync with data=NULL:

Leer descripción completaMostrar menos

While hci_conn_del() dequeues with data=conn:

Since NULL != conn, the lookup in _hci_cmd_sync_lookup_entry() never matches, and the pending work item is not cancelled.

Fix this by saving conn->conn_timeout into a local variable while the locks are still held, so the stale conn pointer is never dereferenced after unlock.

This is the same class of bug as the one fixed by commit 035c25007c9e ("Bluetooth: hci_sync: Fix UAF on le_read_features_complete") which addressed the identical pattern in a different function.

This vulnerability was identified using 0sec.ai, an open-source automated security auditing platform (https://github.com/0sec-labs).

Detalles técnicos trazas, registros y código del informe original

    hci_cmd_sync_queue(hdev, hci_create_cis_sync, NULL, NULL);

    hci_cmd_sync_dequeue(hdev, NULL, conn, NULL);

CVSS

Versión: 3.1
Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Puntuación base: 8.8

Probabilidad de explotación (EPSS)

Probabilidad de explotación en los próximos 30 días: 0.33%
Percentil entre todas las CVEs puntuadas: 24
Fecha de la puntuación: 6/10/2026

EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).

🎯 Técnicas ATT&CK

Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.

ExplotaciónT1210 Exploitation of Remote Serviceslateral movement45 %
Impacto principalT1499.004 Application or System Exploitationimpact55 %
Impacto secundarioT1068 Exploitation for Privilege Escalationprivilege escalation35 %

UAF en controlador Bluetooth local (AV:A, red adyacente). Puede causar DoS o escalada remota tras race condition. Pista sugiere T1210; impactos: crash/DoS y potencial escalada post-explotación.

Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.

🛡️ Mitigaciones ATT&CK que cubren estas técnicas

Threat Intelligence Program Application Isolation and Sandboxing Exploit Protection Update Software Vulnerability Scanning Privileged Account Management

Tecnologías afectadas (1)

⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.

Linux — Linux Kernel^AI

Referencias

JSON original (NVD)

Mostrar

{
  "id": "CVE-2026-63944",
  "cveTags": [],
  "metrics": {
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 8.8,
          "attackVector": "ADJACENT_NETWORK",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "integrityImpact": "HIGH",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "HIGH"
        },
        "impactScore": 5.9,
        "exploitabilityScore": 2.8
      }
    ]
  },
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "c09b80be6ffc338634b2f5f8cfa12b6843410834",
              "lessThan": "a55618c0f4cead9e59c63f5ee030d393fd70d861",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "c09b80be6ffc338634b2f5f8cfa12b6843410834",
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              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "c09b80be6ffc338634b2f5f8cfa12b6843410834",
              "lessThan": "d9019210c8c30d40eb20094274cc647e352f48f7",
              "versionType": "git"
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            {
              "status": "affected",
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              "versionType": "git"
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            {
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              "lessThan": "bfea6091e0fffb270c20e74384b660910277eb6c",
              "versionType": "git"
            }
          ],
          "programFiles": [
            "net/bluetooth/hci_sync.c"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.4"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "6.4",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "6.6.143",
              "versionType": "semver",
              "lessThanOrEqual": "6.6.*"
            },
            {
              "status": "unaffected",
              "version": "6.12.93",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "status": "unaffected",
              "version": "6.18.35",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
            },
            {
              "status": "unaffected",
              "version": "7.0.12",
              "versionType": "semver",
              "lessThanOrEqual": "7.0.*"
            },
            {
              "status": "unaffected",
              "version": "7.1",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "net/bluetooth/hci_sync.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2026-07-19T16:17:12.990",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/380e67b1794a9a281a0cb592b4e62077fbd0c8ca",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/a55618c0f4cead9e59c63f5ee030d393fd70d861",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/a921957d39290143629eb38c4f74b9bef8035d0a",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/bfea6091e0fffb270c20e74384b660910277eb6c",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/d9019210c8c30d40eb20094274cc647e352f48f7",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Awaiting Analysis",
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: hci_sync: fix UAF in hci_le_create_cis_sync\n\nhci_le_create_cis_sync() dereferences conn->conn_timeout after releasing\nboth rcu_read_lock() and hci_dev_lock(hdev).  The conn pointer was\nobtained from an RCU-protected iteration over hdev->conn_hash.list and\nis not valid once these locks are dropped.  A concurrent disconnect can\nfree the hci_conn between the unlock and the dereference, causing a\nuse-after-free read.\n\nThe cancellation mechanism in hci_conn_del() cannot prevent this because\nhci_le_create_cis_pending() queues hci_create_cis_sync with data=NULL:\n\n    hci_cmd_sync_queue(hdev, hci_create_cis_sync, NULL, NULL);\n\nWhile hci_conn_del() dequeues with data=conn:\n\n    hci_cmd_sync_dequeue(hdev, NULL, conn, NULL);\n\nSince NULL != conn, the lookup in _hci_cmd_sync_lookup_entry() never\nmatches, and the pending work item is not cancelled.\n\nFix this by saving conn->conn_timeout into a local variable while the\nlocks are still held, so the stale conn pointer is never dereferenced\nafter unlock.\n\nThis is the same class of bug as the one fixed by commit 035c25007c9e\n(\"Bluetooth: hci_sync: Fix UAF on le_read_features_complete\") which\naddressed the identical pattern in a different function.\n\nThis vulnerability was identified using 0sec.ai, an open-source\nautomated security auditing platform (https://github.com/0sec-labs)."
    }
  ],
  "lastModified": "2026-07-27T17:44:23.777",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}