Auth bypass in Broadcom Rabbitmq Server
CVE-2026-67218
RabbitMQ is a messaging and streaming broker. Prior to versions 4.0.22, 4.1.11, 4.2.6, and 4.3.0, accept_content/2 at line 56 calls rabbit_stream_manager:create_super_stream/... directly after is_authorized (which only checks the management tag + vhost access via is_authorized_vhost). The stream-protocol equivalent (rabbit_stream_reader.erl create_super_stream handler) calls rabbit_stream_utils:check_super_stream_management_permitted/4 which enforces configure on the exchange and each partition queue. The HTTP handler omits this call entirely. A user with management tag and vhost access , but no configure permission on any resource , can create super-streams (an exchange + N partition stream queues + bindings) via the HTTP API. The native stream-protocol path enforces configure on each resource; the HTTP path does not, creating a privilege escalation from 'can view' to 'can create persistent cluster-wide resources.' Preconditions include rabbitmq_stream_management plugin enabled management tag + vhost access (no resource permissions needed). This issue is fixed in versions 4.0.22, 4.1.11, 4.2.6, and 4.3.0.
Vulnerability class: Broken Access Control
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:H.
EPSS exploit prediction
EPSS: 0.004 (31.3th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 31st percentile — 31.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.004 · change: +0.000
Affected products
- Broadcom Rabbitmq Server
- Rabbitmq Rabbitmq-Server — versions >= 4.0.0, < 4.0.22, >= 4.1.0, < 4.1.11, >= 4.2.0, < 4.2.6
Weakness classification (CWE)
References
- github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-34jw-rm7g-hph4 (Vendor Advisory)
- github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.6 (Release Notes)
- github.com/rabbitmq/rabbitmq-server/releases/tag/v4.3.0 (Release Notes)
Frequently asked questions
- What is CVE-2026-67218?
- CVE-2026-67218 is a medium-severity vulnerability in Broadcom Rabbitmq Server, classified under Missing Authorization. CVSS score: 6.5/10. Published 2026-09-23.
- How severe is CVE-2026-67218?
- Medium severity. CVSS v3 base score is 6.5 out of 10.