# CVE-2026-66080: RabbitMQ: Super-stream partitions unbounded allocation

> An attacker with management access can cause denial of service by requesting excessive super-stream partitions, leading to unbounded memory allocation.

- **Severity:** Medium 5.9 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 23 Sep 2026
- **Updated:** 24 Sep 2026
- **Also known as:** BIT-rabbitmq-2026-66080, DEBIAN-CVE-2026-66080, GHSA-wg79-5449-m728, UBUNTU-CVE-2026-66080

## What is CVE-2026-66080?

CVE-2026-66080 is a medium-severity denial of service vulnerability in Broadcom Rabbitmq Server, published on 23 Sep 2026. An attacker needs administrator access to exploit it, with no action from the victim.

### Official description

RabbitMQ is a messaging and streaming broker. Prior to versions 4.1.11, 4.2.6, and 4.3.0, validate_partitions only checks that the requested partition count is at least 1, with no upper bound. A large count such as lists:seq(0, 500000000) allocates roughly 8GB. Preconditions include The rabbitmq_stream_management plugin must be enabled. The caller needs the management tag and access to the target vhost.. This issue is fixed in versions 4.1.11, 4.2.6, and 4.3.0.

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

## Which versions are affected by CVE-2026-66080?

1 open source package ship an affected version, including rabbitmq. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `rabbitmq` | Bitnami | From 4.1.0 | 4.1.11, 4.2.6 |

Products: Broadcom Rabbitmq Server.

## How do I fix CVE-2026-66080?

Upgrade rabbitmq to a fixed version for your release line: 4.1.11 or 4.2.6.

## Is CVE-2026-66080 being exploited?

There is no known exploitation of CVE-2026-66080 in the wild and no public exploit code.

## Other vulnerabilities in Broadcom Rabbitmq Server

- [CVE-2016-9877](https://insights.sbomify.com/CVE-2016-9877/): Auth bypass in Pivotal RabbitMQ 3.x before 3.5.8 and 3.6.x before 3.6.6; RabbitMQ for PCF 1.5.x before 1.5.20, 1.6.x before 1.6.12 and 1.7.x before 1.7.7 (critical 9.8)
- [CVE-2026-67404](https://insights.sbomify.com/CVE-2026-67404/): RabbitMQ: OAuth2 silent verify_none fallback for JWKS fetch (critical 9.2)
- [CVE-2026-67231](https://insights.sbomify.com/CVE-2026-67231/): RabbitMQ: Trust-store whitelist by Issuer+Serial only (critical 9.1)
- [CVE-2026-57219](https://insights.sbomify.com/CVE-2026-57219/): Information disclosure in rabbitmq-server (high 8.7)
- [CVE-2026-67236](https://insights.sbomify.com/CVE-2026-67236/): RabbitMQ: Plaintext username:password stored in an insecure cookie after successful POST /login (high 8.2)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-66080 and fix it if it is affected.

What it is: CVE-2026-66080 is a medium-severity denial of service vulnerability in Broadcom Rabbitmq Server, published on 23 Sep 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-66080 in the wild and no public exploit code.

Affected packages and fixed versions:
- rabbitmq (Bitnami): affected from 4.1.0; fixed in 4.1.11, 4.2.6

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-2026-66080/ (Markdown: https://insights.sbomify.com/CVE-2026-66080/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-66080
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-66080
- OSV: https://osv.dev/vulnerability/CVE-2026-66080

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-66080/
Summaries are generated and may contain mistakes; the official description above is the record.