CVE-2026-66080 RabbitMQ: Super-stream partitions unbounded allocation
An attacker with management access can cause denial of service by requesting excessive super-stream partitions, leading to unbounded memory allocation.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-66080?
CVE-2026-66080 is a medium-severity denial of service vulnerability in Broadcom Rabbitmq Server, published on 23 Sep 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Official description
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.
Weakness: CWE-770
Which versions are affected by CVE-2026-66080?
1 open source package ship an affected version, including rabbitmq. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
rabbitmq Bitnami | From 4.1.0 | 4.1.11, 4.2.6 |
Products include Broadcom Rabbitmq Server.
How do I fix CVE-2026-66080?
Upgrade rabbitmq to a fixed version for your release line: 4.1.11 or 4.2.6.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-66080 being exploited?
There is no known exploitation of CVE-2026-66080 in the wild and no public exploit code.
Other vulnerabilities in Broadcom Rabbitmq Server
- CVE-2016-9877 Auth bypass in Pivotal RabbitMQ 3.x before 3.5.8 and 3.6.x before 3.6.6; RabbitMQ for PCF 1.5.x before 1.5.20, 1.6.x before 1.6.12 and 1.7.x before 1.7.7
- CVE-2026-67404 RabbitMQ: OAuth2 silent verify_none fallback for JWKS fetch
- CVE-2026-67231 RabbitMQ: Trust-store whitelist by Issuer+Serial only
- CVE-2026-57219 Information disclosure in rabbitmq-server
- CVE-2026-67236 RabbitMQ: Plaintext username:password stored in an insecure cookie after successful POST /login
Sources
Also known as BIT-rabbitmq-2026-66080, DEBIAN-CVE-2026-66080, GHSA-wg79-5449-m728, UBUNTU-CVE-2026-66080.