# CVE-2026-99015: Bluetooth: hci_sock: Serialize dead-device detachment


- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Fix available:** Yes
- **Published:** 23 Oct 2026
- **Updated:** 23 Oct 2026
- **Also known as:** AZL-110864, BELL-CVE-2026-99015, DEBIAN-CVE-2026-99015, GHSA-fj4j-9cqw-5cxw, UBUNTU-CVE-2026-99015

## What is CVE-2026-99015?

CVE-2026-99015 is a vulnerability in Linux, published on 23 Oct 2026. 

### Official description

In the Linux kernel, the following vulnerability has been resolved:

Bluetooth: hci_sock: Serialize dead-device detachment

Rebinding an HCI socket after its controller is unregistered can race
monitor control replay and crash the kernel. hci_sock_bind() clears
hci_pi(sk)->hdev and drops the device reference under only the socket
lock, whereas send_monitor_control_replay() holds hci_sk_list.lock for
reading.

Replay can observe a non-NULL hdev, then bind can clear it and drop the
last reference before create_monitor_ctrl_open() reads hdev->id. This
can cause a NULL pointer dereference if the pointer is reloaded, or a
use-after-free if the old pointer is retained.

The kernel reported:

  KASAN: null-ptr-deref in range [0x0000000000000068-0x000000000000006f]
  RIP: 0010:create_monitor_ctrl_open+0x579/0x800
  Call Trace:
   hci_sock_bind+0xd96/0x1190
   __sys_bind+0x166/0x200
   __x64_sys_bind+0x6d/0xb0
   do_syscall_64+0xdd/0x4a0
   entry_SYSCALL_64_after_hwframe+0x77/0x7f

The same missing serialization lets hci_send_to_sock() select a socket
for the old device and queue its frame after bind has detached the socket
or installed a new binding.

Take hci_sk_list.lock for writing when clearing the device pointer and
resetting the socket state. This waits for existing replay and delivery
readers to finish before detachment and prevents later readers from
using the old binding. Keep hci_dev_put() outside the critical section
because the final device release can sleep.

## Which versions are affected by CVE-2026-99015?


## How do I fix CVE-2026-99015?

Upgrade to a fixed version.

## Is CVE-2026-99015 being exploited?

There is no known exploitation of CVE-2026-99015 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-99015 and fix it if it is affected.

What it is: CVE-2026-99015 is a vulnerability in Linux, published on 23 Oct 2026. 
Exploitation: There is no known exploitation of CVE-2026-99015 in the wild and no public exploit code.

Affected product: Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-99015/ (Markdown: https://insights.sbomify.com/CVE-2026-99015/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-99015
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-99015
- OSV: https://osv.dev/vulnerability/CVE-2026-99015

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-99015/
Summaries are generated and may contain mistakes; the official description above is the record.