# CVE-2026-93491: Io.netty/netty-codec-http: netty: denial of service via unbounded httpservercodec http/1.1 pipeline queue


- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Fix available:** Yes
- **Published:** 18 Sep 2026
- **Updated:** 15 Oct 2026
- **Also known as:** CLEANSTART-2026-AI69794, CLEANSTART-2026-FB52227, CLEANSTART-2026-YB51786, DEBIAN-CVE-2026-93491, GHSA-c593-fgx2-8jj6, UBUNTU-CVE-2026-93491

## What is CVE-2026-93491?

CVE-2026-93491 is a high-severity vulnerability in Red Hat AMQ Broker 7, published on 18 Sep 2026. 

### Official description

A flaw was found in Netty's HttpServerCodec. A remote, unauthenticated attacker can exploit this vulnerability by pipelining HTTP/1.1 requests on a single connection and withholding reads. This action causes the methodOverflowQueue to grow without limit, leading to unbounded heap memory consumption and a denial of service due to memory exhaustion.

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

## Which versions are affected by CVE-2026-93491?


## How do I fix CVE-2026-93491?

Upgrade to a fixed version.

## Is CVE-2026-93491 being exploited?

There is no known exploitation of CVE-2026-93491 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-93491 and fix it if it is affected.

What it is: CVE-2026-93491 is a high-severity vulnerability in Red Hat AMQ Broker 7, published on 18 Sep 2026. 
Exploitation: There is no known exploitation of CVE-2026-93491 in the wild and no public exploit code.

Affected product: Red Hat AMQ Broker 7. 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-2026-93491/ (Markdown: https://insights.sbomify.com/CVE-2026-93491/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-93491
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-93491
- OSV: https://osv.dev/vulnerability/CVE-2026-93491

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-93491/
Summaries are generated and may contain mistakes; the official description above is the record.