CVE-2026-77408: rabbitmq amqp091-go Integer Overflow or Wraparound

Vulnerability summary

CVE-2026-77408 is a critical (CVSS 9.1) Integer Overflow or Wraparound vulnerability in rabbitmq amqp091-go. EPSS estimates a 0.52% chance of exploitation in the next 30 days, higher than 43.2% of scored vulnerabilities.

Timeline

1. 16-09-2026
   PublishedVulnerability first disclosed.
2. 16-09-2026
   Last modifiedVulnerability information updated.

Description

RabbitMQ amqp091-go is a Go AMQP 0.9.1 client. Prior to 1.13.0, the writeShortstr function in write.go casts the byte length of AMQP shortstr property values to uint8 without first rejecting values longer than 255 bytes. An application that accepts an oversized CorrelationId, ReplyTo, MessageId, Expiration, UserId, AppId, ContentType, ContentEncoding, or Type value can therefore serialize a wrapped length and only a truncated prefix, while reporting no error. The resulting silent metadata corruption can break request and reply correlation, routing, tracing, and downstream message processing. This issue is fixed in version 1.13.0.

• CWE-190Integer Overflow or WraparoundThe product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.