Resource exhaustion in Broadcom Rabbitmq Server
CVE-2026-66080
RabbitMQ is a messaging and streaming broker. Prior to versions 4.1.11, 4.2.6, and 4.3.0, validate_partitions only checks that the requested partition count is at least 1, with no upper bound. A large count such as lists:seq(0, 500000000) allocates roughly 8GB. Preconditions include The rabbitmq_stream_management plugin must be enabled. The caller needs the management tag and access to the target vhost.. This issue is fixed in versions 4.1.11, 4.2.6, and 4.3.0.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 4.9 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.003 (24.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 25th percentile — 24.6% 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: 0.003 · change: +0.000
Affected products
- Broadcom Rabbitmq Server
- Rabbitmq Rabbitmq-Server — versions >= 4.1.0, < 4.1.11, >= 4.2.0, < 4.2.6
Weakness classification (CWE)
References
- github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-wg79-5449-m728 (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-2026-66080?
- CVE-2026-66080 is a medium-severity vulnerability in Broadcom Rabbitmq Server, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 4.9/10. Published 2026-09-23.
- How severe is CVE-2026-66080?
- Medium severity. CVSS v3 base score is 4.9 out of 10.