# CVE-2026-61634: RabbitMQ Java client accepts broker frames larger than the negotiated AMQP frame_max

> A malicious broker can cause client-side denial of service by sending oversized frames that bypass negotiated limits in the RabbitMQ Java client library.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 18 Aug 2026
- **Updated:** 18 Aug 2026
- **Also known as:** CLEANSTART-2026-KN86223, DEBIAN-CVE-2026-61634, ECHO-18ae-a032-1738, GHSA-5xwg-cfvj-gff5, MINI-599w-36v5-45p5, MINI-fh8r-cgh7-wxc5, MINI-jg3x-88g9-mv6m, MINI-jq9f-6v46-hfqh, MINI-m59m-2v58-55x2, MINI-mh25-xp3f-7xr6, MINI-p5hv-mm5h-gp37, MINI-p757-hc8g-vgm4, MINI-p7m2-669m-j3cg, MINI-q4fc-2mxp-75p4, MINI-q4w6-wq3r-7xwg, MINI-qqf8-fv9x-vpv2, MINI-v4j4-m9g2-rmxj, MINI-vpp9-x2g2-h84h, MINI-w7wg-w358-m35p, UBUNTU-CVE-2026-61634

## What is CVE-2026-61634?

CVE-2026-61634 is a denial of service vulnerability in rabbitmq-java-client, published on 18 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The RabbitMQ Java client library allows Java and JVM-based applications to connect to and interact with RabbitMQ nodes. Prior to 5.33.0, the AMQP connection tuning path records the negotiated AMQP frame_max value, but src/main/java/com/rabbitmq/client/impl/SocketFrameHandler.java and NettyFrameHandlerFactory continue to validate broker-controlled frame payload lengths against maxInboundMessageBodySize because the negotiated limit is not applied consistently through setMaxInboundFramePayloadSize. A malicious or compromised broker can send a method frame larger than the negotiated frame_max during or after connection establishment, causing the client to allocate and decode a protocol-invalid frame instead of rejecting it with MalformedFrameException. The protocol violation can disrupt the affected connection and cause client-side denial of service. This issue is fixed in version 5.33.0.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2026-61634?

2 open source packages ship an affected version, including com.rabbitmq:amqp-client.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `com.rabbitmq:amqp-client` | Maven | All versions | 5.33.0 |
| `com.rabbitmq:amqp-client` | Maven | All versions | 5.33.0 |

## How do I fix CVE-2026-61634?

Upgrade com.rabbitmq:amqp-client to 5.33.0 or later.

## Is CVE-2026-61634 being exploited?

There is no known exploitation of CVE-2026-61634 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-61634 and fix it if it is affected.

What it is: CVE-2026-61634 is a denial of service vulnerability in rabbitmq-java-client, published on 18 Aug 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-2026-61634 in the wild and no public exploit code.

Affected packages and fixed versions:
- com.rabbitmq:amqp-client (Maven): affected all versions; fixed in 5.33.0
- com.rabbitmq:amqp-client (Maven): affected all versions; fixed in 5.33.0

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-2026-61634/ (Markdown: https://insights.sbomify.com/CVE-2026-61634/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-61634
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-61634
- OSV: https://osv.dev/vulnerability/CVE-2026-61634

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-61634/
Summaries are generated and may contain mistakes; the official description above is the record.