# CVE-2026-67420: RabbitMQ OAuth credential refresh retains revoked runtime tags

> Attackers with revoked impersonator tags can retain publishing privileges on existing connections due to stale session state in RabbitMQ OAuth refresh.

- **Severity:** Low 2.3 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 25 Sep 2026
- **Updated:** 29 Sep 2026
- **Also known as:** AZL-105311, BIT-rabbitmq-2026-67420, DEBIAN-CVE-2026-67420, GHSA-86fm-44m9-rqjx, UBUNTU-CVE-2026-67420

## What is CVE-2026-67420?

CVE-2026-67420 is a low-severity vulnerability in Broadcom Rabbitmq Server, published on 25 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

RabbitMQ is a messaging and streaming broker. From 3.13.0 until 3.13.19, 4.0.24, 4.1.15, 4.2.10, and 4.3.5, RabbitMQ OAuth credential refresh retains revoked runtime tags. when an existing AMQP connection refreshes from an OAuth token that grants the impersonator tag to a valid same-username token that no longer grants that tag, RabbitMQ updates the OAuth backend implementation (token/scopes/expiry) but leaves the connection's runtime #user.tags unchanged. rabbitaccesscontrol:checkuserid/2 then still honors the stale impersonator tag, so the connection (including newly opened channels) can continue publishing messages with a foreign AMQP userid after that privilege should have been revoked. A fresh connection using the downgraded token correctly refuses the same publish, proving the defect is stale session state rather than the token Limited to connections that once held impersonator and successfully refresh to a downgraded same-username rabbitauthbackendoauth2 (or an equivalent refresh-capable backend that returns tags) is enabled for This issue is fixed in versions 3.13.19, 4.0.24, 4.1.15, 4.2.10, and 4.3.5.

Weakness: CWE-862 (Missing Authorization)

## Which versions are affected by CVE-2026-67420?

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


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `rabbitmq` | Bitnami | From 3.13.0 | 3.13.19, 4.0.24, 4.1.15, 4.2.10, 4.3.5 |

Products: Broadcom Rabbitmq Server.

## How do I fix CVE-2026-67420?

Upgrade rabbitmq to a fixed version for your release line: 3.13.19, 4.0.24, 4.1.15 or 4.2.10.

## Is CVE-2026-67420 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-67420 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-2026-67420 and fix it if it is affected.

What it is: CVE-2026-67420 is a low-severity vulnerability in Broadcom Rabbitmq Server, published on 25 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-67420 exists.

Affected packages and fixed versions:
- rabbitmq (Bitnami): affected from 3.13.0; fixed in 3.13.19, 4.0.24, 4.1.15, 4.2.10, 4.3.5

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-2026-67420/ (Markdown: https://insights.sbomify.com/CVE-2026-67420/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-67420
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-67420
- OSV: https://osv.dev/vulnerability/CVE-2026-67420

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-67420/
Summaries are generated and may contain mistakes; the official description above is the record.