# CVE-2026-97436: dpaa2-switch: rework FDB management on the bridge leave path

> A logic error in the Linux kernel dpaa2-switch driver causes FDB exhaustion when ports leave bridges, leading to denial of service.

- **Severity:** Not scored
- **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:** 24 Sep 2026
- **Updated:** 3 Oct 2026
- **Also known as:** AZL-103619, BELL-CVE-2026-97436, DEBIAN-CVE-2026-97436, GHSA-6rj6-xm99-p85m, UBUNTU-CVE-2026-97436

## What is CVE-2026-97436?

CVE-2026-97436 is a denial of service vulnerability in Linux, published on 24 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:

dpaa2-switch: rework FDB management on the bridge leave path

On bridge leave, the dpaa2_switch_port_set_fdb() function always
allocates a new FDB for the port which is becoming standalone. In case
no FDB is found, then the port leaving a bridge will continue to use the
current one.

The above logic does not cover the case in which there are multiple
bridges which have ports from the same DPSW instance. In this case, when
the last port leaves bridge #1, it finds an unused FDB to switch to, but
the old FDB is not marked as unused. Since the number of FDBs is equal
to the number of DPSW interfaces, this will eventually lead to multiple
ports sharing the same FDB.

Fix this by changing how we are managing the FDBs on the leave path.
Instead of directly allocating a new FDB, first verify if the current
port is the last one to leave a bridge. If this is the case, then
continue to use the current FDB and only allocate another FDB if there
are other ports remaining in the bridge.

## Which versions are affected by CVE-2026-97436?


## How do I fix CVE-2026-97436?

Apply the vendor's patch.

## Is CVE-2026-97436 being exploited?

There is no known exploitation of CVE-2026-97436 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-97436 and fix it if it is affected.

What it is: CVE-2026-97436 is a denial of service vulnerability in Linux, published on 24 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-2026-97436 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-2026-97436/ (Markdown: https://insights.sbomify.com/CVE-2026-97436/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-97436
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-97436
- OSV: https://osv.dev/vulnerability/CVE-2026-97436

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-97436/
Summaries are generated and may contain mistakes; the official description above is the record.