High 8.8Published Aug 15, 2026

CVE-2026-74509Bluetooth: hci_sync: Fix advertising data UAFs

Updated under an hour ago (Oct 27, 2026, 11:20 AM ET)

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Exploited in the last 30 days

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_sync: Fix advertising data UAFs hci_find_adv_instance() returns an adv_info pointer that is valid only while hdev->lock is held. The advertising command-sync paths perform instance lookups without that lock and, in some cases, retain the pointer while waiting for a controller response. An advertising termination event can therefore interleave as follows: hci_cmd_sync_work hci_rx_work hci_find_adv_instance() __hci_cmd_sync_status() wait for controller reply hci_dev_lock() hci_remove_adv_instance() kfree(adv) adv->scan_rsp_changed = false KASAN reported: BUG: KASAN: slab-use-after-free in hci_set_ext_scan_rsp_data_sync+0x2e1/0x300 Write of size 1 at addr ffff88810a45d21d by task kworker/u17:0/88 Workqueue: hci0 hci_cmd_sync_work Call Trace: hci_set_ext_scan_rsp_data_sync+0x2e1/0x300 hci_schedule_adv_instance_sync+0x390/0x4c0 hci_cmd_sync_work+0x173/0x300 Allocated by task 87: hci_add_adv_instance+0x538/0xac0 add_advertising+0x885/0x1160 Freed by task 89: kfree+0x131/0x3c0 hci_remove_adv_instance+0x1d8/0x3b0 hci_le_ext_adv_term_evt+0x17b/0x730 Protect the instance lookup and payload construction in the extended advertising, scan response, and periodic advertising data paths. Snapshot the advertising parameters under hdev->lock, but release the lock before waiting for the controller. Clear advertising-data dirty bits before issuing their commands and restore them after a failure using a fresh lookup. Likewise, update the reported transmit power through a fresh lookup after the parameter command completes. No adv_info pointer then survives an HCI command wait.

CVSS: 8.8 HIGH (v3.1, CNA)CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness (CWE): Not given
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Linux
NVD analysis: Received
Record last updated: Oct 16, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Linux Linux linux:linux (from the name)	from cba6b758711cab946c787f7c15be92cc749b8e1f before 565971488191bf54a87a417abafab6ad0de72201; from cba6b758711cab946c787f7c15be92cc749b8e1f before c4cec575a6d6f7c36808a3a0017b0675968bb06b; from cba6b758711cab946c787f7c15be92cc749b8e1f before 95cdcd8c82a501931fd3ae9b3811b0b6da167e94; from cba6b758711cab946c787f7c15be92cc749b8e1f before eb1d8318764de7216e6dbba29a24d69f7ce51348; from cba6b758711cab946c787f7c15be92cc749b8e1f before b16ebdbebd2d37f4cdc590bc3e9db71fe90350a3; from cba6b758711cab946c787f7c15be92cc749b8e1f before cdc36db204ffd97b947d64374cf23a210dc74777; 42fe380baaaccbe635c34ca07b29d19b9ec2498d; from 5.15.210 before 5.16	CNA record

References

References

https://git.kernel.org/stable/c/565971488191bf54a87a417abafab6ad0de72201
https://git.kernel.org/stable/c/c4cec575a6d6f7c36808a3a0017b0675968bb06b
https://git.kernel.org/stable/c/95cdcd8c82a501931fd3ae9b3811b0b6da167e94
https://git.kernel.org/stable/c/eb1d8318764de7216e6dbba29a24d69f7ce51348
https://git.kernel.org/stable/c/b16ebdbebd2d37f4cdc590bc3e9db71fe90350a3
https://git.kernel.org/stable/c/cdc36db204ffd97b947d64374cf23a210dc74777

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.