CVE-2026-77408: RabbitMQ amqp091-go: Silent Data Truncation and State Corruption via Shortstr Integer Overflow

A data integrity and protocol corruption vulnerability exists in the AMQP client’s property serialization logic. When encoding AMQP short string (shortstr) fields—such as identifiers, routing strings, and content metadata—the length of the string is explicitly cast to a fixed-size 8-bit unsigned integer (uint8).

If an application provides a property string exceeding 255 bytes, the length counter silently wraps around (e.g., a length of 300 wraps to 44). As a result, the parser writes only a truncated portion of the string into the outgoing connection buffer without returning an error. This leads to silent data corruption, broken RPC routing, and unpredictable broker-side state behavior.