CVE-2026-66072: Rabbitmq Rabbitmq-Server

Medium severity, CVSS 6.0. EPSS: 0.3% chance of exploitation in the next 30 days.

RabbitMQ is a messaging and streaming broker. Prior to versions 3.13.15, 4.0.20, 4.1.11, 4.2.6, and 4.3.1, get_chunk_selector/1 calls binary_to_atom on the raw client-supplied <<"chunk_selector">> property from post-auth subscribe and resolve_offset_spec frames, with no whitelist and no existing guard. An authenticated stream client with read access to any stream can crash the broker node. Preconditions include rabbitmq_stream plugin enabled Authenticated stream-protocol user with read access to at least one stream. This issue is fixed in versions 3.13.15, 4.0.20, 4.1.11, 4.2.6, and 4.3.1.

Affected products

• Rabbitmq Rabbitmq-Server: from 3.13.0, before 3.13.15 (fixed in 3.13.15); from 4.0.0, before 4.0.20 (fixed in 4.0.20); from 4.1.0, before 4.1.11 (fixed in 4.1.11); from 4.2.0, before 4.2.6 (fixed in 4.2.6); from 4.3.0, before 4.3.1 (fixed in 4.3.1)

Published 2026-09-23. Last modified 2026-09-24.