CVE Catalog

CVE-2026-67232

HighCVSS 8.2
Published: Translated: NVD NIST

Summary

RabbitMQ prior to versions 3.13.15, 4.0.20, 4.1.11, 4.2.6, and 4.3.0 enables permessage-deflate WebSocket compression (RFC 7692) without a max_frame_size limit and without an output-size limit on decompression. An unauthenticated attacker can send a highly compressed WebSocket frame (a zlib bomb) that inflates to gigabytes in memory, crashing a RabbitMQ node running the Web-MQTT plugin.

Risk Assessment

An unauthenticated attacker with network access to port 15675/15676 can crash a RabbitMQ node with a single request, causing a denial of service.

Recommendation

Update RabbitMQ to versions 3.13.15, 4.0.20, 4.1.11, 4.2.6, or 4.3.0 and restrict network access to Web-MQTT ports.

Other vulnerabilities in RabbitMQ

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Original NVD description (English source)

RabbitMQ is a messaging and streaming broker. Prior to versions 3.13.15, 4.0.20, 4.1.11, 4.2.6, and 4.3.0, The cowboy WebSocket options at line 117 set compress => true, enabling RFC 7692 permessage-deflate negotiation. The handler does not set max_frame_size, so cowboy's default of infinity applies. cowlib's cow_ws:parse_payload/9 calls zlib:inflate/2 on the compressed payload with no output-size limit. An attacker can negotiate permessage-deflate during the WebSocket upgrade and send a frame containing a zlib bomb (e.g. 50 KB → 5 GB). Decompression occurs in the connection process before websocket_handle/2 ever sees the MQTT bytes. An unauthenticated attacker can crash a RabbitMQ node running the Web-MQTT plugin by sending a single highly-compressed WebSocket frame (a few KB on the wire) that inflates to gigabytes in memory. The cowboy WebSocket handler decompresses the entire frame before the MQTT CONNECT packet is processed, so no credentials are required. Preconditions include rabbitmq_web_mqtt plugin enabled (not default, but common for browser clients) Network reachability to port 15675/15676 No authentication required. This issue is fixed in versions 3.13.15, 4.0.20, 4.1.11, 4.2.6, and 4.3.0.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS