# CVE-2026-98235: net/sched: act_api: release tail references on DELACTION failure

> A reference counting bug in the Linux kernel's traffic control API can lead to memory corruption and potential privilege escalation or denial of service.

- **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:** 6 Oct 2026
- **Updated:** 19 Oct 2026
- **Also known as:** BELL-CVE-2026-98235, DEBIAN-CVE-2026-98235, GHSA-2gfh-v7wp-gcg2, UBUNTU-CVE-2026-98235

## What is CVE-2026-98235?

CVE-2026-98235 is a memory corruption vulnerability in Linux, published on 6 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:

net/sched: act_api: release tail references on DELACTION failure

A batched RTM_DELACTION request takes a temporary reference on each
action before attempting any deletion. tcf_action_delete() clears
each processed slot and drops its temporary reference before attempting
the deletion. If deletion fails, tca_action_gd() calls
tcf_action_put_many() to release the remaining references, but its
tcf_act_for_each_action() iterator stops at the first NULL slot.

When a batch stops at an action bound to a filter, this leaks a
reference on each subsequent action. A later delete of an unbound
action can then return success without removing it from the IDR.

Walk the full array in tcf_action_put_many() and skip NULL slots to
release the references held on the unprocessed actions.

## Which versions are affected by CVE-2026-98235?


## How do I fix CVE-2026-98235?

Apply the vendor's patch.

## Is CVE-2026-98235 being exploited?

There is no known exploitation of CVE-2026-98235 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-98235 and fix it if it is affected.

What it is: CVE-2026-98235 is a memory corruption vulnerability in Linux, published on 6 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-2026-98235 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-2026-98235/ (Markdown: https://insights.sbomify.com/CVE-2026-98235/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-98235
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-98235
- OSV: https://osv.dev/vulnerability/CVE-2026-98235

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-98235/
Summaries are generated and may contain mistakes; the official description above is the record.