CVE-2026-68339 Bluetooth: btusb: validate Realtek vendor event length
A missing length check in the Linux kernel Bluetooth driver allows reading adjacent memory, potentially disclosing sensitive information to nearby attackers.
- 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-2026-68339?
CVE-2026-68339 is a vulnerability in Linux, published on 10 Aug 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: validate Realtek vendor event length
btusb_recv_event_realtek() reads the event code at data[0] and the Realtek subevent code at data[2] before deciding whether to consume a vendor event as a coredump.
For example, the two-byte event ff 00 contains a complete vendor-event header declaring zero parameters. The old classifier still reads a nonexistent third byte and can misclassify the event as a coredump if the adjacent byte is 0x34.
Require the HCI event header and first parameter to be present before inspecting the Realtek subevent code. Short events continue through the normal HCI receive path, which owns their protocol validation.
Which versions are affected by CVE-2026-68339?
How do I fix CVE-2026-68339?
Apply the vendor's patch.
Is CVE-2026-68339 being exploited?
There is no known exploitation of CVE-2026-68339 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-68339, DEBIAN-CVE-2026-68339, GHSA-mvcc-3q4w-wxx6, UBUNTU-CVE-2026-68339.