# CVE-2026-98625: netfilter: flowtable: publish HW_DEAD after worker is done

> A use-after-free in the Linux kernel netfilter flowtable allows attackers to execute arbitrary code or escalate privileges via race conditions.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 18 Oct 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-108737, BELL-CVE-2026-98625, DEBIAN-CVE-2026-98625, GHSA-42xw-mjh5-fhf4, UBUNTU-CVE-2026-98625

## What is CVE-2026-98625?

CVE-2026-98625 is an use after free vulnerability in Linux, published on 18 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

netfilter: flowtable: publish HW_DEAD after worker is done

flow_offload_work_del() sets NF_FLOW_HW_DEAD before the work handler
clears NF_FLOW_HW_PENDING. Once a flow is both HW_DYING and HW_DEAD, a
concurrent garbage collection pass can remove it and schedule it for RCU
freeing.

The offload worker holds neither an RCU read lock nor a reference to the
flow. If it is preempted after publishing HW_DEAD, the RCU callback can
free the flow before the worker resumes and clears HW_PENDING, resulting
in a use-after-free.

Move HW_DEAD publication to the common worker epilogue after the pending
bit is cleared, making it the final flow access by destroy work. Order all
preceding flow accesses before publishing the bit that allows garbage
collection to free the object.

## Which versions are affected by CVE-2026-98625?


## How do I fix CVE-2026-98625?

Apply the vendor's patch.

## Is CVE-2026-98625 being exploited?

There is no known exploitation of CVE-2026-98625 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-98625 and fix it if it is affected.

What it is: CVE-2026-98625 is an use after free vulnerability in Linux, published on 18 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-98625 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-2026-98625/ (Markdown: https://insights.sbomify.com/CVE-2026-98625/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-98625
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-98625
- OSV: https://osv.dev/vulnerability/CVE-2026-98625

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-98625/
Summaries are generated and may contain mistakes; the official description above is the record.