# CVE-2026-90092: Bluetooth: L2CAP: reject accept queue add unless BT_LISTEN

> A race condition in the Linux kernel Bluetooth L2CAP subsystem allows a use-after-free, potentially leading to code execution or privilege escalation.

- **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:** 17 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-102993, BELL-CVE-2026-90092, DEBIAN-CVE-2026-90092, GHSA-6f8j-3px9-h4jj, UBUNTU-CVE-2026-90092

## What is CVE-2026-90092?

CVE-2026-90092 is a high-severity use after free vulnerability in Linux, published on 17 Sep 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: reject accept queue add unless BT_LISTEN

New sk should not be added to parent socket accept queue after last
l2cap_sock_cleanup_listen() has run in l2cap_sock_teardown_cb() and
state set to BT_CLOSED, as that can result to UAF on dereferencing the
dangling parent reference.

l2cap_sock_new_connection_cb() may race with parent l2cap_chan teardown,
due to chan->state accessed without consistent locking:

  [Task 1]                           [Task 2]
  l2cap_sock_release(parent)         l2cap_connect
    l2cap_sock_shutdown                pchan = l2cap_global_chan_by_psm
      l2cap_chan_lock(pchan)
      l2cap_chan_close
        l2cap_sock_teardown_cb
          pchan->state = BT_CLOSED
      l2cap_chan_unlock(pchan) ------> l2cap_chan_lock(pchan)
                                       l2cap_new_connection
                                         l2cap_sock_new_connection_cb
      l2cap_chan_lock(pchan) <-------- l2cap_chan_unlock(pchan)
      l2cap_sock_kill(parent)          /* bt_sk(sk)->parent dangling */

Fix by adding check for sk_state == BT_LISTEN after acquiring sk lock in
l2cap_sock_new_connection_cb().  Add lock_sock() around sk_state writes
where missing, to avoid data races.

Although the data races on pchan->state should be fixed too, this
defensive sk_state check probably makes sense in any case.

## Which versions are affected by CVE-2026-90092?


## How do I fix CVE-2026-90092?

Apply the vendor's patch.

## Is CVE-2026-90092 being exploited?

There is no known exploitation of CVE-2026-90092 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-90092 and fix it if it is affected.

What it is: CVE-2026-90092 is a high-severity use after free vulnerability in Linux, published on 17 Sep 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-2026-90092 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-2026-90092/ (Markdown: https://insights.sbomify.com/CVE-2026-90092/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-90092
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-90092
- OSV: https://osv.dev/vulnerability/CVE-2026-90092

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-90092/
Summaries are generated and may contain mistakes; the official description above is the record.