What’s Vulnerable › Vulnerabilities

CVE-2026-77406: RabbitMQ amqp091-go: Consumer Message Flooding via Signed-to-Unsigned Integer Casting in Qos Configuration

• Severity: high (CVSS 8.2 v4.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-09-16 · updated 2026-09-23
• Weakness: CWE-195

Description

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.

Affected products

• rabbitmq amqp091-go: before 1.13.0

References

• https://github.com/rabbitmq/amqp091-go/commit/3b879e1d1d25b544e26b3bc3d7db3213203c0f3b
• https://github.com/rabbitmq/amqp091-go/pull/351
• https://github.com/rabbitmq/amqp091-go/releases/tag/v1.13.0
• https://github.com/rabbitmq/amqp091-go/security/advisories/GHSA-rm6m-hrcw-jw33

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