# CVE-2026-82439: Apache Storm DRPC: Unauthenticated Unbounded Memory Growth in DRPC

> Unauthenticated attackers can cause permanent memory exhaustion in Apache Storm DRPC by sending unique function names, leading to denial of service.

- **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-q5hq-8q75-r6f6

## What is CVE-2026-82439?

CVE-2026-82439 is a critical denial of service vulnerability in Apache Storm DRPC, 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 DRPC server kept a map from function name to request queue and created an entry the first time a
function name was seen. No code path ever removed an entry: request cleanup removed the request from its
queue, and the shutdown path drained queues, but the queue object and its map entry remained for the life of
the process.

Function names come from the client and are not constrained to functions any topology has registered, so the
number of retained entries is bounded only by the number of distinct names an attacker chooses to send, and
each retained entry holds the name itself. `drpc.authorizer` is unset by default, so no credentials are
required to reach the endpoint.

The retained state is permanent rather than a transient load spike, so the effect accumulates until the DRPC
server exhausts its heap.

Mitigation

Upgrade to 3.1.0, where a function's queue is removed once nothing is waiting in it.

Users who cannot upgrade immediately should configure `drpc.authorizer` so that only trusted principals can
reach the DRPC endpoints, and should ensure the DRPC ports are not reachable from untrusted networks.

Credit

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

Weakness: CWE-770 (Allocation of Resources Without Limits or Throttling)

## Which versions are affected by CVE-2026-82439?


## How do I fix CVE-2026-82439?

No fix has been published for CVE-2026-82439 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-82439 being exploited?

There is no known exploitation of CVE-2026-82439 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-82439 and fix it if it is affected.

What it is: CVE-2026-82439 is a critical denial of service vulnerability in Apache Storm DRPC, 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-2026-82439 in the wild and no public exploit code.

Affected product: Apache Storm DRPC. 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-2026-82439/ (Markdown: https://insights.sbomify.com/CVE-2026-82439/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-82439
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-82439
- OSV: https://osv.dev/vulnerability/CVE-2026-82439

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-82439/
Summaries are generated and may contain mistakes; the official description above is the record.