{"id":"CVE-2026-63944","revision":"435384e38f3f48839f5c3e21338a7377","records":[{"revision":"435384e38f3f48839f5c3e21338a7377","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-63944","aliases":[],"title":"Bluetooth: hci_sync: fix UAF in hci_le_create_cis_sync","description":"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).","state":0,"publishedAt":"2026-07-19T14:55:39.105+00:00","modifiedAt":"2026-10-19T20:17:58.398+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"net/bluetooth/hci_sync.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"c09b80be6ffc338634b2f5f8cfa12b6843410834\",\n                            \"lessThan\": \"a55618c0f4cead9e59c63f5ee030d393fd70d861\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"c09b80be6ffc338634b2f5f8cfa12b6843410834\",\n                            \"lessThan\": \"a921957d39290143629eb38c4f74b9bef8035d0a\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"c09b80be6ffc338634b2f5f8cfa12b6843410834\",\n                            \"lessThan\": \"d9019210c8c30d40eb20094274cc647e352f48f7\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"c09b80be6ffc338634b2f5f8cfa12b6843410834\",\n                            \"lessThan\": \"380e67b1794a9a281a0cb592b4e62077fbd0c8ca\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"c09b80be6ffc338634b2f5f8cfa12b6843410834\",\n                            \"lessThan\": \"bfea6091e0fffb270c20e74384b660910277eb6c\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"net/bluetooth/hci_sync.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"6.4\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"6.4\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.143\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.93\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.35\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.0.12\",\n                            \"lessThanOrEqual\": \"7.0.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.1\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","score":8.8,"severity":"HIGH"}],"references":["https://git.kernel.org/stable/c/a55618c0f4cead9e59c63f5ee030d393fd70d861","https://git.kernel.org/stable/c/a921957d39290143629eb38c4f74b9bef8035d0a","https://git.kernel.org/stable/c/d9019210c8c30d40eb20094274cc647e352f48f7","https://git.kernel.org/stable/c/380e67b1794a9a281a0cb592b4e62077fbd0c8ca","https://git.kernel.org/stable/c/bfea6091e0fffb270c20e74384b660910277eb6c"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-63944","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-63944","identifiers":["CVE-2026-63944"]},"retained":false,"historicalAffected":[]}],"coverage":[]}