CVE-2026-66076: RabbitMQ: Cross-vhost quorum-queue status and stream tracking disclosure

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-09-23 · updated 2026-10-19
Weakness: CWE-862

Description

RabbitMQ is a messaging and streaming broker. Prior to versions 3.13.15, 4.0.20, 4.1.11, 4.2.6, and 4.3.0, is_authorized/2 calls rabbit_mgmt_util:is_authorized/2, which checks only the management tag, instead of is_authorized_vhost/2. The /api/queues/quorum/:vhost/:queue/status handler reads the vhost from the path without checking that the user can access it. Any management-tagged user can therefore read Raft status, including leader, members, term, and commit index, for quorum queues in inaccessible vhosts, exposing cross-tenant queue names and cluster topology. The management plugin must be enabled and the attacker must have a management tag. This issue is fixed in versions 3.13.15, 4.0.20, 4.1.11, 4.2.6, and 4.3.0.

Affected products

rabbitmq-server: from 3.13.0 before 3.13.15; from 4.0.0 before 4.0.20; from 4.1.0 before 4.1.11; from 4.2.0 before 4.2.6 — fixed in 3.13.15, 4.0.20, 4.1.11, 4.2.6

How to fix

Upgrade to a fixed version: rabbitmq-server 3.13.15, 4.0.20, 4.1.11, 4.2.6. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2026-66076 or the next vulnerability affects your stack