CVE-2026-66080

What it is

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.

At a glance

Exploitability

Can be exploited over the network with an admin-level account. High risk of service disruption.

Exploit odds

0.3% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-09-23 21:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-10-19 20:37 UTC Last updatedMost recent change to the record

Details

Published

2026-09-23 21:16 UTC

Last modified

2026-10-19 20:37 UTC

Exploit probability

0.3% · EPSS, next 30 days

Weakness

CWE-770 · Allocation without limits

Record status

Analyzed

Affected

• Broadcom Rabbitmq Server < 4.1.11
• Broadcom Rabbitmq Server < 4.2.6

Attack profile CVSS 4.0 · 5.9

Attack vector

Network

Complexity

Low

Attack requirements

Present

Privileges needed

High

User interaction

None

Confidentiality

None

Integrity

None

Availability

High