# CVE-2026-97616: net/sched: act_api: release all action references on NEWACTION failure

> A local attacker with high privileges can cause a resource leak in the Linux kernel traffic control subsystem, leading to 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:** 25 Sep 2026
- **Updated:** 21 Oct 2026
- **Also known as:** AZL-104505, BELL-CVE-2026-97616, DEBIAN-CVE-2026-97616, GHSA-rpwr-33rh-mw75, UBUNTU-CVE-2026-97616

## What is CVE-2026-97616?

CVE-2026-97616 is a denial of service vulnerability in Linux, published on 25 Sep 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 all action references on NEWACTION failure

When a batched RTM_NEWACTION request replaces an existing action,
tcf_idr_check_alloc() takes a temporary reference on it. If a later
action fails to initialize, tcf_action_destroy() uses strict release
semantics to clean up the actions initialized so far. For an action
bound to a filter, the strict check returns -EPERM without dropping
the temporary reference.

This error also makes tcf_action_destroy() return before releasing
subsequent entries. Any new action initialized between the bound
action and the failing entry is leaked together with its reserved
IDR slot, preventing reuse of its index.

Use tcf_idr_release() to drop each reference held by the batch without
rejecting bound actions. This allows cleanup to continue through all
initialized entries and preserves the module reference release when
an action is destroyed. Explicit action deletion and flushing retain
their separate bind-count checks.

## Which versions are affected by CVE-2026-97616?


## How do I fix CVE-2026-97616?

Apply the vendor's patch.

## Is CVE-2026-97616 being exploited?

There is no known exploitation of CVE-2026-97616 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-97616 and fix it if it is affected.

What it is: CVE-2026-97616 is a denial of service vulnerability in Linux, published on 25 Sep 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-2026-97616 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-2026-97616/ (Markdown: https://insights.sbomify.com/CVE-2026-97616/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-97616
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-97616
- OSV: https://osv.dev/vulnerability/CVE-2026-97616

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-97616/
Summaries are generated and may contain mistakes; the official description above is the record.