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.

CVSS 4.0

5.9CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

CVSS 3.1

4.9CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H

EPSS

0.3% chance of exploitation in the next 30 days; higher than 24% of CVEs (scores of 2026-10-25)

CWE

CWE-770

Published

2026-09-23

Modified

2026-10-19

Record from

the NVD, synced 2026-10-21

Affected

• broadcom:rabbitmq_server

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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