# CVE-2026-67226: RabbitMQ: Admin-only atom exhaustion: PUT /api/users tags list

> An administrator can crash the RabbitMQ node by submitting a user creation request with an excessive number of tags, causing resource exhaustion.

- **Severity:** Medium 6.9 (`CVSS:4.0/AV:N/AC:L/AT:N/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:** 25 Sep 2026
- **Updated:** 25 Sep 2026
- **Also known as:** AZL-105765, BIT-rabbitmq-2026-67226, DEBIAN-CVE-2026-67226, GHSA-34c7-r8w9-5wv8, UBUNTU-CVE-2026-67226

## What is CVE-2026-67226?

CVE-2026-67226 is a medium-severity denial of service vulnerability in Broadcom Rabbitmq Server, published on 25 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. From 4.0.0 until 4.0.22 and 4.1.14 and 4.2.7, Admin-only atom exhaustion: PUT /api/users tags list. settags/2 maps rabbitdatacoercion:toatom/1 over the user's tags list. The 20 MB management body limit fits ~3-4M short tag strings. An administrator can crash the node in a single request by creating a user (or importing definitions) with ~1M unique tag administrator. This issue is fixed in versions 4.0.22 and 4.1.14 and 4.2.7.

Weakness: CWE-400 (Uncontrolled Resource Consumption)

## Which versions are affected by CVE-2026-67226?

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


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `rabbitmq` | Bitnami | From 4.0.0 | 4.0.22, 4.1.14, 4.2.7 |

Products: Broadcom Rabbitmq Server.

## How do I fix CVE-2026-67226?

Upgrade rabbitmq to a fixed version for your release line: 4.0.22, 4.1.14 or 4.2.7.

## Is CVE-2026-67226 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-67226 exists.

## 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-2026-67226 and fix it if it is affected.

What it is: CVE-2026-67226 is a medium-severity denial of service vulnerability in Broadcom Rabbitmq Server, published on 25 Sep 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-67226 exists.

Affected packages and fixed versions:
- rabbitmq (Bitnami): affected from 4.0.0; fixed in 4.0.22, 4.1.14, 4.2.7

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-2026-67226/ (Markdown: https://insights.sbomify.com/CVE-2026-67226/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-67226
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-67226
- OSV: https://osv.dev/vulnerability/CVE-2026-67226

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-67226/
Summaries are generated and may contain mistakes; the official description above is the record.