# CVE-2026-46111: Bluetooth: hci_conn: fix potential UAF in create_big_sync

> A use-after-free in the Linux kernel Bluetooth subsystem allows attackers to execute arbitrary code or escalate privileges via crafted Bluetooth connections.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/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:** 28 May 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-89007, BELL-CVE-2026-46111, DEBIAN-CVE-2026-46111, GHSA-926m-qfg2-2w89, ROOT-OS-DEBIAN-12-CVE-2026-46111, ROOT-OS-UBUNTU-2404-CVE-2026-46111, UBUNTU-CVE-2026-46111

## What is CVE-2026-46111?

CVE-2026-46111 is a high-severity use after free vulnerability in Linux kernel, published on 28 May 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_conn: fix potential UAF in create_big_sync

Add hci_conn_valid() check in create_big_sync() to detect stale
connections before proceeding with BIG creation. Handle the
resulting -ECANCELED in create_big_complete() and re-validate the
connection under hci_dev_lock() before dereferencing, matching the
pattern used by create_le_conn_complete() and create_pa_complete().

Keep the hci_conn object alive across the async boundary by taking
a reference via hci_conn_get() when queueing create_big_sync(), and
dropping it in the completion callback. The refcount and the lock
are complementary: the refcount keeps the object allocated, while
hci_dev_lock() serializes hci_conn_hash_del()'s list_del_rcu() on
hdev->conn_hash, as required by hci_conn_del().

hci_conn_put() is called outside hci_dev_unlock() so the final put
(which resolves to kfree() via bt_link_release) does not run under
hdev->lock, though the release path would be safe either way.

Without this, create_big_complete() would unconditionally
dereference the conn pointer on error, causing a use-after-free
via hci_connect_cfm() and hci_conn_del().

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2026-46111?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-46111?

Apply the vendor's patch.

## Is CVE-2026-46111 being exploited?

There is no known exploitation of CVE-2026-46111 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-2026-46111 and fix it if it is affected.

What it is: CVE-2026-46111 is a high-severity use after free vulnerability in Linux kernel, published on 28 May 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-2026-46111 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-2026-46111/ (Markdown: https://insights.sbomify.com/CVE-2026-46111/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-46111
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-46111
- OSV: https://osv.dev/vulnerability/CVE-2026-46111

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-46111/
Summaries are generated and may contain mistakes; the official description above is the record.