# CVE-2026-63946: Bluetooth: ISO: fix UAF in iso_recv_frame

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

- **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:** 19 Jul 2026
- **Updated:** 19 Oct 2026
- **Also known as:** BELL-CVE-2026-63946, DEBIAN-CVE-2026-63946, GHSA-9g79-vcq4-5rfr, UBUNTU-CVE-2026-63946

## What is CVE-2026-63946?

CVE-2026-63946 is a high-severity use after free vulnerability in Linux kernel, published on 19 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: ISO: fix UAF in iso_recv_frame

iso_recv_frame reads conn->sk under iso_conn_lock but releases the lock
before using sk, with no reference held. A concurrent iso_sock_kill()
can free sk in that window, causing use-after-free on sk->sk_state and
sock_queue_rcv_skb().

Fix by replacing the bare pointer read with iso_sock_hold(conn), which
calls sock_hold() while the spinlock is held, atomically elevating the
refcount before the lock drops. Add a drop_put label so sock_put() is
called on all exit paths where the hold succeeded.

Weakness: CWE-362 (Concurrent Execution using Shared Resource with Improper Synchronization), CWE-416 (Use After Free)

## Which versions are affected by CVE-2026-63946?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-63946?

Apply the vendor's patch.

## Is CVE-2026-63946 being exploited?

There is no known exploitation of CVE-2026-63946 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-2026-63946 and fix it if it is affected.

What it is: CVE-2026-63946 is a high-severity use after free vulnerability in Linux kernel, published on 19 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-2026-63946 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-2026-63946/ (Markdown: https://insights.sbomify.com/CVE-2026-63946/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-63946
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-63946
- OSV: https://osv.dev/vulnerability/CVE-2026-63946

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-63946/
Summaries are generated and may contain mistakes; the official description above is the record.