AMQP 0.9.1 Client Vulnerability in RabbitMQ's Go Implementation
CVE-2026-77403

8.9HIGH

Key Information:

Vendor

RabbitMQ

Status
AMQp091-go
Vendor
CVE Published:
16 September 2026

What is CVE-2026-77403?

The RabbitMQ amqp091-go client prior to version 1.13.0 contains a flaw in the Connection.openTune function where it permits a server to advertise a FrameMax value lower than the AMQP protocol's minimum frame size of 4096 bytes. This oversight in connection negotiation can be exploited by malicious brokers to set extremely low FrameMax values, resulting in client publications being excessively fragmented. The fragmentation can lead to increased CPU consumption and potential stalling of the client or hosting environment. The issue has been rectified in version 1.13.0.

Affected Version(s)

amqp091-go < 1.13.0

References

https://github.com/rabbitmq/amqp091-go/security/advisorie...
x_refsource_CONFIRM
https://github.com/rabbitmq/amqp091-go/pull/353
x_refsource_MISC
https://github.com/rabbitmq/amqp091-go/commit/2e0a919b89f...
x_refsource_MISC

CVSS V4

Score:
8.9
Severity:
HIGH
Confidentiality:
None
Integrity:
None
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
Physical
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.