CVE-2026-77403: Rabbitmq AMQP091-Go

High severity, CVSS 8.9. EPSS: 0.5% chance of exploitation in the next 30 days.

RabbitMQ amqp091-go is a Go AMQP 0.9.1 client. Prior to 1.13.0, Connection.openTune in connection.go accepts a server-advertised FrameMax below the AMQP frameMinSize value of 4096 bytes because the connection negotiation loop does not enforce the protocol minimum. A malicious or compromised AMQP broker can therefore advertise an extremely small FrameMax, causing later client publications to be fragmented into excessive numbers of frames and write operations. This can consume CPU and stall the client or its host. This issue is fixed in version 1.13.0.

Affected products

• Rabbitmq AMQP091-Go: before 1.13.0 (fixed in 1.13.0)

Published 2026-09-16. Last modified 2026-09-23.