# CVE-2026-93558: Denial of service in Red Hat AMQ Broker 7

> Remote attackers can cause denial of service in Netty-based servers by exploiting unbounded queue growth in WebSocket handling via HTTP pipelining.

- **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
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 18 Sep 2026
- **Updated:** 15 Oct 2026
- **Also known as:** DEBIAN-CVE-2026-93558, GHSA-wfpc-rccm-rq4m, UBUNTU-CVE-2026-93558

## What is CVE-2026-93558?

CVE-2026-93558 is a high-severity denial of service vulnerability in Red Hat AMQ Broker 7, published on 18 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A flaw was found in Netty's WebSocketServerExtensionHandler. A remote, unauthenticated attacker can exploit this vulnerability by using HTTP/1.1 pipelining to send requests faster than the application can respond. This leads to an unbounded growth of a per-connection queue, consuming excessive memory. Eventually, this can cause the Java Virtual Machine (JVM) to exhaust its heap, resulting in a Denial of Service (DoS) for the affected server.

Weakness: CWE-1035

## Which versions are affected by CVE-2026-93558?


## How do I fix CVE-2026-93558?

Upgrade to a fixed version.

## Is CVE-2026-93558 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-93558 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-93558 and fix it if it is affected.

What it is: CVE-2026-93558 is a high-severity denial of service vulnerability in Red Hat AMQ Broker 7, published on 18 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-93558 exists.

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-2026-93558/ (Markdown: https://insights.sbomify.com/CVE-2026-93558/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-93558
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-93558
- OSV: https://osv.dev/vulnerability/CVE-2026-93558

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-93558/
Summaries are generated and may contain mistakes; the official description above is the record.