Vulnerability in Rabbitmq Amqp091-Go

CVE-2026-77406

RabbitMQ amqp091-go is a Go AMQP 0.9.1 client. Prior to 1.13.0, Channel.Qos in channel.go accepts negative prefetchCount and prefetchSize integers and casts them directly to uint16 and uint32 fields in the basic.qos method because validateQos is absent. Values such as -1 therefore wrap to 65535 or 4294967295 instead of being rejected. An application that permits untrusted configuration of these Qos values can unintentionally request extremely large prefetch limits, allowing a broker to deliver enough queued messages to exhaust client memory and disrupt processing. This issue is fixed in version 1.13.0.

Published · last modified .

EPSS exploit prediction

EPSS: 0.005 (44.4th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 44th percentile — 44.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-77406: held from 0.004 to 0.005.

EPSS over last 30 days · oldest: 0.004 · newest: 0.005 · change: +0.001

Affected products

Weakness classification (CWE)

References