CVE-2026-98456 Bluetooth: mgmt: fix race in read_unconf_index_list()
A race condition in the Linux kernel Bluetooth management allows an out-of-bounds write, potentially leading to code execution or denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-98456?
CVE-2026-98456 is a high-severity vulnerability in Linux, published on 18 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: mgmt: fix race in read_unconf_index_list()
read_unconf_index_list() counts unconfigured controllers before allocating its response, then checks the device flags again while filling it.
hci_dev_list_lock stabilizes list membership, but it does not serialize the per-device flags. During asynchronous controller setup, the worker can set HCI_UNCONFIGURED and clear HCI_SETUP between the two passes. A controller omitted from the allocation count can then become eligible for the fill pass, causing an out-of-bounds write to rp->index[].
Allocate space for every device on hci_dev_list. Since list membership cannot change while hci_dev_list_lock is held, the response remains large enough regardless of flag transitions. The reported count and response length still include only eligible unconfigured controllers.
Which versions are affected by CVE-2026-98456?
How do I fix CVE-2026-98456?
Apply the vendor's patch.
Is CVE-2026-98456 being exploited?
There is no known exploitation of CVE-2026-98456 in the wild and no public exploit code.
Sources
Also known as AZL-108825, BELL-CVE-2026-98456, DEBIAN-CVE-2026-98456, GHSA-79jp-j4mv-p57c, UBUNTU-CVE-2026-98456.