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 Sep 23, 2026
  • CVSS 5.9 medium
  • 0.3% chance of exploitation in the next 30 days (EPSS)
  • A fix is available

Affected software

CVE-2026-66080 at the National Vulnerability Database