CVE-2026-61634

Summary

The max body size was enforced to patch CVE-2023-46120, but even though that limit still works, the frame size itself still exceeds the given max size.

Root cause

The Java client records the AMQP 0-9-1 frame_max negotiated during connection tuning, but the socket inbound frame reader continues to validate broker-controlled payload lengths against the much larger maxInboundMessageBodySize limit. A broker peer can therefore send a method frame whose payload is larger than the negotiated frame_max, have it allocated and decoded, and complete the connection handshake instead of being rejected as a protocol violation.

Reported by Team Atlanta.

The library allows Java code to interface to AMQP servers. Please see the specification page for more information on AMQP inter-operation and standards-conformance You will need an AMQP server, such as our very own RabbitMQ server, to use with the client library.

Security Fix(es):

The RabbitMQ Java client library allows Java and JVM-based applications to connect to and interact with RabbitMQ nodes. maxBodyLebgth was not used when receiving Message objects. Attackers could send a very large Message causing a memory overflow and triggering an OOM Error. Users of RabbitMQ may suffer from DoS attacks from RabbitMQ Java client which will ultimately exhaust the memory of the consumer. This vulnerability was patched in version 5.18.0.(CVE-2023-46120)

The RabbitMQ Java client library allows Java and JVM-based applications to connect to and interact with RabbitMQ nodes. Prior to 5.33.0, the AMQP connection tuning path records the negotiated AMQP frame_max value, but src/main/java/com/rabbitmq/client/impl/SocketFrameHandler.java and NettyFrameHandlerFactory continue to validate broker-controlled frame payload lengths against maxInboundMessageBodySize because the negotiated limit is not applied consistently through setMaxInboundFramePayloadSize. A malicious or compromised broker can send a method frame larger than the negotiated frame_max during or after connection establishment, causing the client to allocate and decode a protocol-invalid frame instead of rejecting it with MalformedFrameException. The protocol violation can disrupt the affected connection and cause client-side denial of service. This issue is fixed in version 5.33.0.(CVE-2026-61634)

The RabbitMQ Java client library allows Java and JVM-based applications to connect to and interact with RabbitMQ nodes. Prior to 5.31.0, inbound AMQP command assembly in src/main/java/com/rabbitmq/client/impl/CommandAssembler.java processes a content-bearing method and header whose remainingBodyBytes value is smaller than a following AMQP.FRAME_BODY payload. CommandAssembler.consumeBodyFrame subtracts the peer-controlled payload length before validating that it fits, drives remainingBodyBytes negative, and throws a raw UnsupportedOperationException instead of MalformedFrameException. A malicious or compromised broker peer can send this malformed sequence on an open nonzero channel to terminate frame processing and close the client connection, causing denial of service for work using that connection. This issue is fixed in version 5.31.0.(CVE-2026-63335)

The RabbitMQ Java client library allows Java and JVM-based applications to connect to and interact with RabbitMQ nodes. Prior to 5.33.0, com.rabbitmq.client.ConnectionFactory.useSslProtocol() and ConnectionFactory.useSslProtocol(String) configure com.rabbitmq.client.TrustEverythingTrustManager and leave hostname verification disabled, causing arbitrary server certificates, including self-signed certificates, to be accepted. A network attacker able to intercept a TLS connection can impersonate the RabbitMQ broker, read protected AMQP traffic, and modify traffic without certificate or hostname validation. The fix changes the production TLS helpers to use the JVM default trust store and enables hostname verification, while retaining an explicitly named development-only no-verification helper. This issue is fixed in version 5.33.0.(CVE-2026-63336)

The RabbitMQ Java client library allows Java and JVM-based applications to connect to and interact with RabbitMQ nodes. Prior to 5.33.1, src/main/java/com/rabbitmq/client/impl/ValueReader.java uses ValueReader.readBytes to accept a wire-declared contentLength below Integer.MAX_VALUE and allocate a byte array before checking the bytes available in the frame. A malicious AMQP peer can send a LongString or byte-array field with type tag S and a declared length such as 0x7FFFFFFE during the pre-authentication connection.start server-properties table, causing an approximately 2 GB allocation and…

The RabbitMQ Java client library allows Java and JVM-based applications to connect to and interact with RabbitMQ nodes. Prior to 5.33.0, the AMQP connection tuning path records the negotiated AMQP frame_max value, but src/main/java/com/rabbitmq/client/impl/SocketFrameHandler.java and NettyFrameHandlerFactory continue to validate broker-controlled frame payload lengths against maxInboundMessageBodySize because the negotiated limit is not applied consistently through setMaxInboundFramePayloadSize. A malicious or compromised broker can send a method frame larger than the negotiated frame_max during or after connection establishment, causing the client to allocate and decode a protocol-invalid frame instead of rejecting it with MalformedFrameException. The protocol violation can disrupt the affected connection and cause client-side denial of service. This issue is fixed in version 5.33.0.

TuxCare rebuilt com.rabbitmq:amqp-client to address 4 CVEs. Fixed in 5.19.0-tuxcare.2.