CVE-2026-43018 Bluetooth: hci_event: fix potential UAF in hci_le_remote_conn_param_req_evt
A use-after-free vulnerability in the Linux kernel Bluetooth subsystem allows attackers to execute arbitrary code or escalate privileges via concurrent connection handling.
- 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-2026-43018?
CVE-2026-43018 is a high-severity use after free vulnerability in Linux kernel, published on 1 May 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_event: fix potential UAF in hci_le_remote_conn_param_req_evt
hci_conn lookup and field access must be covered by hdev lock in hci_le_remote_conn_param_req_evt, otherwise it's possible it is freed concurrently.
Extend the hci_dev_lock critical section to cover all conn usage.
Weakness: CWE-416
Which versions are affected by CVE-2026-43018?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-43018?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2026-43018 being exploited?
There is no known exploitation of CVE-2026-43018 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2026-43018, DEBIAN-CVE-2026-43018, GHSA-6jmv-jjw5-5rwp, ROOT-OS-UBUNTU-2404-CVE-2026-43018, UBUNTU-CVE-2026-43018.