# CVE-2026-98624: netfilter: nfnetlink_queue: hold nfnl mutex in event notifier

> A race condition in the Linux kernel netfilter module allows local attackers to cause a system crash via concurrent netlink operations.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 18 Oct 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-109172, BELL-CVE-2026-98624, DEBIAN-CVE-2026-98624, GHSA-6phv-j3wg-rfjh, UBUNTU-CVE-2026-98624

## What is CVE-2026-98624?

CVE-2026-98624 is a vulnerability in Linux, published on 18 Oct 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:

netfilter: nfnetlink_queue: hold nfnl mutex in event notifier

We must serialize the release notifier and the config netlink function.
A concurrent thread can issue close() which can call the release function
while unrelated socket processes UNBIND request for same portid:

Oops: general protection fault, [..]
RIP: 0010:__instance_destroy+0x60/0x210 [nfnetlink_queue]
Call Trace:
 nfqnl_recv_config+0x9b0/0xdc0 [nfnetlink_queue]
 nfnetlink_rcv_msg+0x7c2/0xeb0
 ? __pfx_nfnetlink_rcv_msg+0x10/0x10

After this, parallel UNBIND and URELEASE events are impossible.

This change isn't nice, but its the shortest fix given instances
are not refcounted and the nfnetlink config callback drops the
rcu read lock early due to need for sleeping allocations.

## Which versions are affected by CVE-2026-98624?


## How do I fix CVE-2026-98624?

Apply the vendor's patch.

## Is CVE-2026-98624 being exploited?

There is no known exploitation of CVE-2026-98624 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-98624 and fix it if it is affected.

What it is: CVE-2026-98624 is a vulnerability in Linux, published on 18 Oct 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-2026-98624 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-2026-98624/ (Markdown: https://insights.sbomify.com/CVE-2026-98624/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-98624
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-98624
- OSV: https://osv.dev/vulnerability/CVE-2026-98624

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-98624/
Summaries are generated and may contain mistakes; the official description above is the record.