{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-74509","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-08-15T05:44:03.909Z","datePublished":"2026-08-15T12:27:31.896Z","dateUpdated":"2026-08-23T12:47:29.942Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-23T12:47:29.942Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: hci_sync: Fix advertising data UAFs\n\nhci_find_adv_instance() returns an adv_info pointer that is valid only\nwhile hdev->lock is held.  The advertising command-sync paths perform\ninstance lookups without that lock and, in some cases, retain the pointer\nwhile waiting for a controller response.\n\nAn advertising termination event can therefore interleave as follows:\n\n  hci_cmd_sync_work                 hci_rx_work\n  hci_find_adv_instance()\n  __hci_cmd_sync_status()\n    wait for controller reply       hci_dev_lock()\n                                    hci_remove_adv_instance()\n                                      kfree(adv)\n  adv->scan_rsp_changed = false\n\nKASAN reported:\n\n  BUG: KASAN: slab-use-after-free in hci_set_ext_scan_rsp_data_sync+0x2e1/0x300\n  Write of size 1 at addr ffff88810a45d21d by task kworker/u17:0/88\n  Workqueue: hci0 hci_cmd_sync_work\n  Call Trace:\n   hci_set_ext_scan_rsp_data_sync+0x2e1/0x300\n   hci_schedule_adv_instance_sync+0x390/0x4c0\n   hci_cmd_sync_work+0x173/0x300\n  Allocated by task 87:\n   hci_add_adv_instance+0x538/0xac0\n   add_advertising+0x885/0x1160\n  Freed by task 89:\n   kfree+0x131/0x3c0\n   hci_remove_adv_instance+0x1d8/0x3b0\n   hci_le_ext_adv_term_evt+0x17b/0x730\n\nProtect the instance lookup and payload construction in the extended\nadvertising, scan response, and periodic advertising data paths.  Snapshot\nthe advertising parameters under hdev->lock, but release the lock before\nwaiting for the controller.\n\nClear advertising-data dirty bits before issuing their commands and\nrestore them after a failure using a fresh lookup.  Likewise, update the\nreported transmit power through a fresh lookup after the parameter command\ncompletes.  No adv_info pointer then survives an HCI command wait."}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","baseScore":8.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:A - The bug is in the Bluetooth HCI LE extended-advertising path; a remote/adjacent peer can deliver the LE Extended Advertising Set Terminated HCI event that frees adv_info while hci_cmd_sync_work waits on the controller during scan-response/advertising-data updates on phones and other BLE devices.\nAC:L - This is a use-after-free race between hci_cmd_sync_work and hci_rx_work where the attacker controls the terminating side by repeatedly initiating BLE connections/terminations during the up-to-2s HCI command wait, and can also drive the setup side via MGMT advertising commands.\nPR:N - An adjacent Bluetooth attacker needs no account, credentials, or capabilities on the victim; exploitation only requires the victim stack to be configuring BLE advertising (normal on Android phones, laptops, and IoT) while the attacker sends over-the-air BLE traffic to trigger hci_le_ext_adv_term_evt.\nUI:N - No deliberate victim action is required beyond a device running Bluetooth with LE advertising updates (common default behavior); the attacker triggers the race remotely without social engineering, file opens, or mounts.\nS:U - Impact is kernel heap corruption and potential local privilege escalation within the same kernel security domain; it does not cross a VM, container, or IOMMU boundary.\nC:H - Multiple UAF paths read freed adv_info (e.g., eir_create_scan_rsp/adv_data) and retain dangling pointers across __hci_cmd_sync_status waits, enabling slab reuse and arbitrary kernel memory disclosure via heap grooming.\nI:H - KASAN shows a post-free write to adv_info (scan_rsp_changed); similar paths write adv_data_changed and tx_power on freed objects, providing exploitable heap corruption for arbitrary kernel writes and code execution.\nA:H - Use-after-free on adv_info in hci_cmd_sync_work can cause immediate kernel oops/panic or hung BLE subsystem during advertising reconfiguration, and is reachable from unauthenticated adjacent BLE interaction on actively advertising devices."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/bluetooth/hci_sync.c"],"versions":[{"version":"cba6b758711cab946c787f7c15be92cc749b8e1f","lessThan":"565971488191bf54a87a417abafab6ad0de72201","status":"affected","versionType":"git"},{"version":"cba6b758711cab946c787f7c15be92cc749b8e1f","lessThan":"95cdcd8c82a501931fd3ae9b3811b0b6da167e94","status":"affected","versionType":"git"},{"version":"cba6b758711cab946c787f7c15be92cc749b8e1f","lessThan":"eb1d8318764de7216e6dbba29a24d69f7ce51348","status":"affected","versionType":"git"},{"version":"cba6b758711cab946c787f7c15be92cc749b8e1f","lessThan":"b16ebdbebd2d37f4cdc590bc3e9db71fe90350a3","status":"affected","versionType":"git"},{"version":"cba6b758711cab946c787f7c15be92cc749b8e1f","lessThan":"cdc36db204ffd97b947d64374cf23a210dc74777","status":"affected","versionType":"git"},{"version":"42fe380baaaccbe635c34ca07b29d19b9ec2498d","status":"affected","versionType":"git"},{"version":"5.15.210","lessThan":"5.16","status":"affected","versionType":"semver"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/bluetooth/hci_sync.c"],"versions":[{"version":"5.17","status":"affected"},{"version":"0","lessThan":"5.17","status":"unaffected","versionType":"semver"},{"version":"6.1.184","lessThanOrEqual":"6.1.*","status":"unaffected","versionType":"semver"},{"version":"6.12.103","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.44","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.1.8","lessThanOrEqual":"7.1.*","status":"unaffected","versionType":"semver"},{"version":"7.2","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.17","versionEndExcluding":"6.1.184"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.17","versionEndExcluding":"6.12.103"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.17","versionEndExcluding":"6.18.44"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.17","versionEndExcluding":"7.1.8"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.17","versionEndExcluding":"7.2"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15.210"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/565971488191bf54a87a417abafab6ad0de72201"},{"url":"https://git.kernel.org/stable/c/95cdcd8c82a501931fd3ae9b3811b0b6da167e94"},{"url":"https://git.kernel.org/stable/c/eb1d8318764de7216e6dbba29a24d69f7ce51348"},{"url":"https://git.kernel.org/stable/c/b16ebdbebd2d37f4cdc590bc3e9db71fe90350a3"},{"url":"https://git.kernel.org/stable/c/cdc36db204ffd97b947d64374cf23a210dc74777"}],"title":"Bluetooth: hci_sync: Fix advertising data UAFs","x_generator":{"engine":"bippy-1.2.0"}}}}