Auth bypass in Broadcom Rabbitmq Server
CVE-2026-66075
RabbitMQ is a messaging and streaming broker. Prior to versions 3.13.15, 4.0.20, 4.1.11, 4.2.6, and 4.3.1, is_authorized/2 for the /federation-links/.../restart route uses is_authorized_monitor (accepts the monitoring tag), while allowed_methods permits DELETE and delete_resource/2 triggers rabbit_federation_link_sup:restart. There is no per-method elevation check and no comment marking it intentional. A read-only monitoring user can restart any federation link , a state-changing operation that disrupts message flow. Preconditions include rabbitmq_federation + rabbitmq_federation_management plugins enabled Attacker has credentials with the monitoring tag. This issue is fixed in versions 3.13.15, 4.0.20, 4.1.11, 4.2.6, and 4.3.1.
Vulnerability class: Broken Access Control
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L.
EPSS exploit prediction
EPSS: 0.002 (13.2th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 13th percentile — 13.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: -0.000
Affected products
- Broadcom Rabbitmq Server
- Rabbitmq Rabbitmq-Server — versions >= 3.13.0, < 3.13.15, >= 4.0.0, < 4.0.20, >= 4.1.0, < 4.1.11
Weakness classification (CWE)
References
- github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-g5v3-w5xg-62q2 (Vendor Advisory)
- github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.6 (Release Notes)
- github.com/rabbitmq/rabbitmq-server/releases/tag/v4.3.1 (Release Notes)
Frequently asked questions
- What is CVE-2026-66075?
- CVE-2026-66075 is a medium-severity vulnerability in Broadcom Rabbitmq Server, classified under Missing Authorization. CVSS score: 5.4/10. Published 2026-09-23.
- How severe is CVE-2026-66075?
- Medium severity. CVSS v3 base score is 5.4 out of 10.