# CVE-2026-64206: Bluetooth: L2CAP: cancel pending_rx_work before taking conn->lock

> A race condition in the Linux kernel Bluetooth L2CAP module can cause a deadlock during connection teardown, leading to a denial of service.

- **Severity:** High 8.8 (`CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 20 Jul 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-92865, BELL-CVE-2026-64206, DEBIAN-CVE-2026-64206, GHSA-4pqq-whjc-554c, ROOT-OS-DEBIAN-11-CVE-2026-64206, ROOT-OS-DEBIAN-12-CVE-2026-64206, ROOT-OS-DEBIAN-13-CVE-2026-64206, ROOT-OS-UBUNTU-2204-CVE-2026-64206, UBUNTU-CVE-2026-64206

## What is CVE-2026-64206?

CVE-2026-64206 is a high-severity vulnerability in Linux kernel, published on 20 Jul 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: L2CAP: cancel pending_rx_work before taking conn->lock

l2cap_conn_del() takes conn->lock and then calls cancel_work_sync() for
pending_rx_work.  process_pending_rx() takes the same mutex, so teardown
can deadlock against the worker it is flushing.

This issue was found by our static analysis tool and then manually
reviewed against the current tree.

The grounded PoC kept the l2cap_conn_ready() -> queue_work(...,
&conn->pending_rx_work) submit path, the l2cap_conn_del() ->
cancel_work_sync(&conn->pending_rx_work) teardown path, and the
process_pending_rx() -> mutex_lock(&conn->lock) worker edge.  Lockdep

  WARNING: possible circular locking dependency detected
  process_pending_rx+0x21/0x2a [vuln_msv]
  l2cap_conn_del.constprop.0+0x3f/0x4e [vuln_msv]
  *** DEADLOCK ***

Cancel pending_rx_work before taking conn->lock, matching the existing
lock-before-drain ordering used for the two delayed works in the same
teardown path.  The pending_rx queue is still purged after the work has
been cancelled and conn->lock has been acquired.

Weakness: CWE-362 (Concurrent Execution using Shared Resource with Improper Synchronization)

## Which versions are affected by CVE-2026-64206?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-64206?

Apply the vendor's patch.

## Is CVE-2026-64206 being exploited?

There is no known exploitation of CVE-2026-64206 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-64206 and fix it if it is affected.

What it is: CVE-2026-64206 is a high-severity vulnerability in Linux kernel, published on 20 Jul 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-64206 in the wild and no public exploit code.

Affected product: Linux kernel. 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-2026-64206/ (Markdown: https://insights.sbomify.com/CVE-2026-64206/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-64206
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-64206
- OSV: https://osv.dev/vulnerability/CVE-2026-64206

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-64206/
Summaries are generated and may contain mistakes; the official description above is the record.