CVE-2026-53276 Bluetooth: ISO: Fix a use-after-free of the hci_conn pointer
A use-after-free in the Linux kernel Bluetooth ISO subsystem allows attackers to potentially execute code or escalate privileges via concurrent socket operations.
- 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-2026-53276?
CVE-2026-53276 is a high-severity use after free vulnerability in Linux kernel, published on 25 Jun 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: ISO: Fix a use-after-free of the hci_conn pointer
In iso_sock_rebind_bc(), the bis pointer is cached, then the socket lock is dropped: bis = iso_pi(sk)->conn->hcon; /* Release the socket before lookups since that requires hci_dev_lock * which shall not be acquired while holding sock_lock for proper * ordering. */ release_sock(sk); hci_dev_lock(bis->hdev);
During the unlocked window, could a concurrent close() destroy the connection and free the bis structure, causing hci_dev_lock(bis->hdev) to access memory after it is freed, fix this by using the hdev reference which was safely acquired via iso_conn_get_hdev().
Weakness: CWE-416
Which versions are affected by CVE-2026-53276?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-53276?
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-2026-53276 being exploited?
There is no known exploitation of CVE-2026-53276 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as DEBIAN-CVE-2026-53276, GHSA-h5cp-pgfw-22wh, UBUNTU-CVE-2026-53276.