# CVE-2026-82435: Apache Storm Worker: Unauthenticated Remote Memory Exhaustion in the Worker Messaging Decoder

> Unauthenticated remote attackers can cause denial of service in Apache Storm Workers by sending crafted frames that trigger excessive memory allocation before authentication.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 14 Sep 2026
- **Updated:** 14 Sep 2026
- **Also known as:** GHSA-3mpj-29mm-p7wr

## What is CVE-2026-82435?

CVE-2026-82435 is a critical denial of service vulnerability in Apache Storm Worker, published on 14 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Description

The worker's Netty message decoder is installed ahead of the SASL authentication handlers in the pipeline
and acts on frames before any authentication has taken place. It allocated buffers sized from a
length field carried in the frame, so a single frame from an unauthenticated peer able to reach a worker
slot port could drive a large allocation.

`storm.messaging.netty.authentication` defaults to false, and the decoder runs before the handler that
enforces it in any case, so no credentials are required. The attacker needs only TCP reachability to a
worker port.

The effect of a single frame at the default 768 MB worker heap has not been measured to distinguish
sustained worker loss from transient garbage-collection pressure. The severity assigned to this advisory
reflects the more conservative reading; consumers who require a precise figure should test against their own
worker heap configuration.

Mitigation

Upgrade to 3.1.0, where frames are decoded only after the handshake completes.

Users who cannot upgrade immediately should ensure that worker slot ports are reachable only from within the
cluster, as the security model already recommends, and should enable
`storm.messaging.netty.authentication` where the deployment permits it.

Credit

The ASF -- found using Claude agents to study the security of open-source projects, validated and reported by Apache Storm.

Weakness: CWE-789 (Memory Allocation with Excessive Size Value)

## Which versions are affected by CVE-2026-82435?


## How do I fix CVE-2026-82435?

No fix has been published for CVE-2026-82435 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-82435 being exploited?

There is no known exploitation of CVE-2026-82435 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-82435 and fix it if it is affected.

What it is: CVE-2026-82435 is a critical denial of service vulnerability in Apache Storm Worker, published on 14 Sep 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-2026-82435 in the wild and no public exploit code.

Affected product: Apache Storm Worker. 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-2026-82435/ (Markdown: https://insights.sbomify.com/CVE-2026-82435/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-82435
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-82435
- OSV: https://osv.dev/vulnerability/CVE-2026-82435

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-82435/
Summaries are generated and may contain mistakes; the official description above is the record.