CVE-2026-98247 Bluetooth: hci_codec: validate vendor codec count length
A missing length check in the Linux kernel Bluetooth codec parser allows a local attacker to cause a denial of service via out-of-bounds read.
- 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-2026-98247?
CVE-2026-98247 is a denial of service vulnerability in Linux, published on 6 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: hci_codec: validate vendor codec count length
The Read Local Supported Codecs parsers consume the variable-sized standard codec array before parsing the vendor codec count. Although the initial reply-size check includes a vendor count byte in the fixed layout, it does not guarantee that the byte remains after the standard codec array.
If a controller reply ends immediately after that array, calculating the vendor codec array size reads vnd_codecs->num beyond the skb data. Use skb_pull_data() to validate and consume each codec header before using its count in both command variants.
Which versions are affected by CVE-2026-98247?
How do I fix CVE-2026-98247?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-98247 being exploited?
There is no known exploitation of CVE-2026-98247 in the wild and no public exploit code.
Sources
Also known as AZL-106200, BELL-CVE-2026-98247, DEBIAN-CVE-2026-98247, GHSA-w49g-pfqv-m398, UBUNTU-CVE-2026-98247.