CVE-2025-39861 Bluetooth: vhci: Prevent use-after-free by removing debugfs files early

High 7.8 Published 19 Sep 2025 Updated 11 May 2026

A use-after-free vulnerability in the Linux kernel Bluetooth vhci driver allows attackers to potentially execute code or escalate privileges via debugfs access.

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-2025-39861?

CVE-2025-39861 is a high-severity use after free vulnerability in Linux kernel, published on 19 Sep 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: vhci: Prevent use-after-free by removing debugfs files early

Move the creation of debugfs files into a dedicated function, and ensure they are explicitly removed during vhci_release(), before associated data structures are freed.

Previously, debugfs files such as "force_suspend", "force_wakeup", and others were created under hdev->debugfs but not removed in vhci_release(). Since vhci_release() frees the backing vhci_data structure, any access to these files after release would result in use-after-free errors.

Although hdev->debugfs is later freed in hci_release_dev(), user can access files after vhci_data is freed but before hdev->debugfs is released.

Weakness: CWE-416

Which versions are affected by CVE-2025-39861?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2025-39861?

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-2025-39861 being exploited?

There is no known exploitation of CVE-2025-39861 in the wild and no public exploit code.

All Linux kernel vulnerabilities

Sources

Also known as AZL-67572, BELL-CVE-2025-39861, DEBIAN-CVE-2025-39861, GHSA-j8g4-37fg-mjm8, ROOT-OS-DEBIAN-13-CVE-2025-39861, ROOT-OS-UBUNTU-2404-CVE-2025-39861 and 1 more.