# CVE-2026-74530: Bluetooth: hci_sync: hold conn in hci_connect_big_sync() callback

> A use-after-free vulnerability in the Linux kernel Bluetooth subsystem allows attackers to potentially execute code or escalate privileges.

- **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:** 15 Aug 2026
- **Updated:** 21 Oct 2026
- **Also known as:** BELL-CVE-2026-74530, DEBIAN-CVE-2026-74530, GHSA-65qm-758v-r47w, UBUNTU-CVE-2026-74530

## What is CVE-2026-74530?

CVE-2026-74530 is a high-severity use after free vulnerability in Linux, published on 15 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_sync: hold conn in hci_connect_big_sync() callback

There is theoretical UAF if the conn is freed while the hci_sync task is
running.

Hold refcount to avoid that. Handle NULL hcon, return 0 + do nothing to
match the previous behavior.

## Which versions are affected by CVE-2026-74530?


## How do I fix CVE-2026-74530?

Apply the vendor's patch.

## Is CVE-2026-74530 being exploited?

There is no known exploitation of CVE-2026-74530 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-74530 and fix it if it is affected.

What it is: CVE-2026-74530 is a high-severity use after free vulnerability in Linux, published on 15 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-2026-74530 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-2026-74530/ (Markdown: https://insights.sbomify.com/CVE-2026-74530/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-74530
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-74530
- OSV: https://osv.dev/vulnerability/CVE-2026-74530

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-74530/
Summaries are generated and may contain mistakes; the official description above is the record.