CVE-2026-97408 Bluetooth: L2CAP: validate connectionless PSM length
A missing length check in the Linux kernel Bluetooth L2CAP parser allows attackers to read out-of-bounds memory via malformed connectionless frames.
- 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-2026-97408?
CVE-2026-97408 is a vulnerability in Linux, published on 24 Sep 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: L2CAP: validate connectionless PSM length
Connectionless L2CAP frames carry a two-byte PSM at the start of the payload. l2cap_recv_frame() currently reads that PSM unconditionally after validating only the outer L2CAP length.
A malformed connectionless frame with a zero- or one-byte payload can therefore make the parser read beyond the advertised skb payload and use tailroom bytes as part of the PSM. A VHCI-backed QEMU reproducer injected a one-byte connectionless payload and reached the unchecked read.
Reject connectionless frames that cannot contain the PSM before reading or pulling it. This preserves all valid connectionless frames while dropping only structurally incomplete packets.
Which versions are affected by CVE-2026-97408?
How do I fix CVE-2026-97408?
Apply the vendor's patch.
Is CVE-2026-97408 being exploited?
There is no known exploitation of CVE-2026-97408 in the wild and no public exploit code.
Sources
Also known as AZL-104042, BELL-CVE-2026-97408, DEBIAN-CVE-2026-97408, GHSA-39rm-4xq5-hvr6, UBUNTU-CVE-2026-97408.