# CVE-2026-68085: Bluetooth: hci_uart: clear HCI_UART_SENDING when write_work is canceled

> A race condition in the Linux kernel Bluetooth driver fails to clear a state flag, causing a denial of service by blocking future writes after device reopening.

- **Severity:** High 8.0 (`CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **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:** Yes
- **Published:** 10 Aug 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-95147, BELL-CVE-2026-68085, DEBIAN-CVE-2026-68085, GHSA-mhcf-ghw6-c6wv, UBUNTU-CVE-2026-68085

## What is CVE-2026-68085?

CVE-2026-68085 is a high-severity vulnerability in Linux, published on 10 Aug 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: hci_uart: clear HCI_UART_SENDING when write_work is canceled

HCI_UART_SENDING bit in tx_state means write_work is pending and blocks
queueing it again.  Currently this bit is not cleared when canceling the
work in hci_uart_close(), which blocks future writes when device is
reopened later if write_work was pending.

Fix by clearing HCI_UART_SENDING when canceling the work.

Also make clearing of tx_skb safe by using disable_work_sync +
enable_work instead of just cancel_work_sync.  hci_uart_flush() purges
the proto tx queue so we can cancel the pending write_work there,
instead of doing it just in hci_uart_close().  Re-enable and possibly
requeue the work after queue flush.

Weakness: CWE-667 (Improper Locking)

## Which versions are affected by CVE-2026-68085?


## How do I fix CVE-2026-68085?

Apply the vendor's patch.

## Is CVE-2026-68085 being exploited?

There is no known exploitation of CVE-2026-68085 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-68085 and fix it if it is affected.

What it is: CVE-2026-68085 is a high-severity vulnerability in Linux, published on 10 Aug 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-2026-68085 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-2026-68085/ (Markdown: https://insights.sbomify.com/CVE-2026-68085/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-68085
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-68085
- OSV: https://osv.dev/vulnerability/CVE-2026-68085

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-68085/
Summaries are generated and may contain mistakes; the official description above is the record.