What’s Vulnerable › Vulnerabilities

CVE-2026-66080: RabbitMQ: Super-stream partitions unbounded allocation

• Severity: medium (CVSS 4.9 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-770

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.

Affected products

• rabbitmq-server: from 4.1.0 before 4.1.11; from 4.2.0 before 4.2.6 — fixed in 4.1.11, 4.2.6

How to fix

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

References

• https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.6
• https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.3.0
• https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-wg79-5449-m728

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