CVE-2023-54210 Bluetooth: hci_sync: Avoid use-after-free in dbg for hci_remove_adv_monitor()
A use-after-free vulnerability in the Linux kernel's Bluetooth HCI subsystem allows attackers to cause a denial of service or potentially execute code.
- 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-2023-54210?
CVE-2023-54210 is a high-severity use after free vulnerability in Linux, published on 30 Dec 2025. 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_sync: Avoid use-after-free in dbg for hci_remove_adv_monitor()
KASAN reports that there's a use-after-free in hci_remove_adv_monitor(). Trawling through the disassembly, you can see that the complaint is from the access in bt_dev_dbg() under the HCI_ADV_MONITOR_EXT_MSFT case. The problem case happens because msft_remove_monitor() can end up freeing the monitor structure. Specifically: hci_remove_adv_monitor() -> msft_remove_monitor() -> msft_remove_monitor_sync() -> msft_le_cancel_monitor_advertisement_cb() -> hci_free_adv_monitor()
Let's fix the problem by just stashing the relevant data when it's still valid.
Which versions are affected by CVE-2023-54210?
How do I fix CVE-2023-54210?
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-2023-54210 being exploited?
There is no known exploitation of CVE-2023-54210 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2023-54210, DEBIAN-CVE-2023-54210, GHSA-58q4-73m8-4p8p, UBUNTU-CVE-2023-54210.