{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "c09b80be6ffc338634b2f5f8cfa12b6843410834"
            },
            {
              "fixed": "a55618c0f4cead9e59c63f5ee030d393fd70d861"
            },
            {
              "fixed": "a921957d39290143629eb38c4f74b9bef8035d0a"
            },
            {
              "fixed": "d9019210c8c30d40eb20094274cc647e352f48f7"
            },
            {
              "fixed": "380e67b1794a9a281a0cb592b4e62077fbd0c8ca"
            },
            {
              "fixed": "bfea6091e0fffb270c20e74384b660910277eb6c"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "6.4.0"
            },
            {
              "fixed": "6.6.143"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.12.93"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.35"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.0.12"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/63xxx/CVE-2026-63944.json"
  },
  "details": "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-\u003econn_timeout after releasing\nboth rcu_read_lock() and hci_dev_lock(hdev).  The conn pointer was\nobtained from an RCU-protected iteration over hdev-\u003econn_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-\u003econn_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).",
  "id": "CVE-2026-63944",
  "modified": "2026-07-22T05:29:53.524496902Z",
  "published": "2026-07-19T14:55:39.105Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/380e67b1794a9a281a0cb592b4e62077fbd0c8ca"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a55618c0f4cead9e59c63f5ee030d393fd70d861"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a921957d39290143629eb38c4f74b9bef8035d0a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/bfea6091e0fffb270c20e74384b660910277eb6c"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d9019210c8c30d40eb20094274cc647e352f48f7"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/63xxx/CVE-2026-63944.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-63944"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.8.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Bluetooth: hci_sync: fix UAF in hci_le_create_cis_sync"
}