{"cve":"CVE-2026-74509","nvd":{"published":"2026-08-15T13:17:55.950","modified":"2026-10-16T20:17:33.550","status":"Received","description":"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.","cvss_v4":null,"cvss_v3":{"version":"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},"cwes":[],"references":["https://git.kernel.org/stable/c/565971488191bf54a87a417abafab6ad0de72201","https://git.kernel.org/stable/c/95cdcd8c82a501931fd3ae9b3811b0b6da167e94","https://git.kernel.org/stable/c/b16ebdbebd2d37f4cdc590bc3e9db71fe90350a3","https://git.kernel.org/stable/c/c4cec575a6d6f7c36808a3a0017b0675968bb06b","https://git.kernel.org/stable/c/cdc36db204ffd97b947d64374cf23a210dc74777"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:49:10.689564601+00:00"},"epss":{"cve":"CVE-2026-74509","score":0.00249,"percentile":0.16084,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}