Microsoft Security Response Center guidance
Vendor revision: Nov 5, 2026Release Notes
Vulnerability intelligence
CVE-2026-43119 and is rated Medium severity with a CVSS score of 5.5. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.
Release Notes
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: hci_sync: annotate data-races around hdev->req_status
__hci_cmd_sync_sk() sets hdev->req_status under hdev->req_lock:
hdev->req_status = HCI_REQ_PEND;
However, several other functions read or write hdev->req_status without holding any lock:
- hci_send_cmd_sync() reads req_status in hci_cmd_work (workqueue) - hci_cmd_sync_complete() reads/writes from HCI event completion - hci_cmd_sync_cancel() / hci_cmd_sync_cancel_sync() read/write - hci_abort_conn() reads in connection abort path
Since __hci_cmd_sync_sk() runs on hdev->req_workqueue while hci_send_cmd_sync() runs on hdev->workqueue, these are different workqueues that can execute concurrently on different CPUs. The plain C accesses constitute a data race.
Add READ_ONCE()/WRITE_ONCE() annotations on all concurrent accesses to hdev->req_status to prevent potential compiler optimizations that could affect correctness (e.g., load fusing in the wait_event condition or store reordering).
Source: NVD