CVE-2026-31497 Bluetooth: btusb: clamp SCO altsetting table indices
An out-of-bounds read in the Linux kernel Bluetooth driver allows attackers to cause a denial of service or leak memory information.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-31497?
CVE-2026-31497 is a medium-severity memory corruption vulnerability in Linux kernel, published on 22 Apr 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: btusb: clamp SCO altsetting table indices
btusb_work() maps the number of active SCO links to USB alternate settings through a three-entry lookup table when CVSD traffic uses transparent voice settings. The lookup currently indexes alts[] with data->sco_num - 1 without first constraining sco_num to the number of available table entries.
While the table only defines alternate settings for up to three SCO links, data->sco_num comes from hci_conn_num() and is used directly. Cap the lookup to the last table entry before indexing it so the driver keeps selecting the highest supported alternate setting without reading past alts[].
Which versions are affected by CVE-2026-31497?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-31497?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-31497 being exploited?
There is no known exploitation of CVE-2026-31497 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-83240, BELL-CVE-2026-31497, DEBIAN-CVE-2026-31497, GHSA-5324-g7qj-pjfx, ROOT-OS-DEBIAN-11-CVE-2026-31497, ROOT-OS-DEBIAN-12-CVE-2026-31497 and 3 more.