CVE-2025-38128 Bluetooth: MGMT: reject malformed HCI_CMD_SYNC commands

Medium 5.5 Published Updated

A missing size check in the Linux kernel Bluetooth management allows attackers to trigger memory corruption via malformed HCI commands.

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-2025-38128?

CVE-2025-38128 is a medium-severity memory corruption vulnerability in Linux kernel, published on 3 Jul 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: MGMT: reject malformed HCI_CMD_SYNC commands

In 'mgmt_hci_cmd_sync()', check whether the size of parameters passed in 'struct mgmt_cp_hci_cmd_sync' matches the total size of the data (i.e. 'sizeof(struct mgmt_cp_hci_cmd_sync)' plus trailing bytes). Otherwise, large invalid 'params_len' will cause 'hci_cmd_sync_alloc()' to do 'skb_put_data()' from an area beyond the one actually passed to 'mgmt_hci_cmd_sync()'.

Which versions are affected by CVE-2025-38128?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2025-38128?

Apply the vendor's patch.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2025-38128 being exploited?

There is no known exploitation of CVE-2025-38128 in the wild and no public exploit code.

All Linux kernel vulnerabilities

Sources

Also known as BELL-CVE-2025-38128, GHSA-x4w4-294m-j35h, UBUNTU-CVE-2025-38128.

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