# CVE-2026-77412: RabbitMQ amqp091-go denial of service via malicious field length

Source: https://junglewise.ai/threats/cve-2026-77412-rabbitmq-amqp091-go-denial-of-service-via-malicious-field-length  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-16. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-77412 · Severity: high · CVSS 4 · Published 2026-09-16

The RabbitMQ Go AMQP client library contains a flaw that allows a malicious or compromised message broker to crash client applications. When the client receives a specially crafted message frame with an invalid field length, it triggers an unrecoverable crash of the entire process. This creates a denial-of-service condition where legitimate applications using this library lose connectivity and functionality.

Technologies: [github.com/rabbitmq/amqp091-go (Go)](https://junglewise.ai/threats/technologies/github-com-rabbitmq-amqp091-go), [RabbitMQ Amqp091-Go](https://junglewise.ai/threats/technologies/amqp091-go). Vendors: [Go](https://junglewise.ai/threats/vendors/go), [RabbitMQ](https://junglewise.ai/threats/vendors/rabbitmq).

## Quick answers

**Is CVE-2026-77412 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-77412 being exploited in the wild.

**How severe is CVE-2026-77412?** High severity, with a CVSS score of 4, published 16 September 2026.

**Which products and versions are affected?** github.com/rabbitmq/amqp091-go (Go) < 1.13.0, SEMVER:introduced=0,fixed=1.13.0; RabbitMQ Amqp091-Go <UNKNOWN>.

**Is there a fix for CVE-2026-77412?** Yes. github.com/rabbitmq/amqp091-go (Go): upgrade to 1.13.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-77412 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-77412?** Check whether you run github.com/rabbitmq/amqp091-go (Go) or RabbitMQ Amqp091-Go at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- github.com/rabbitmq/amqp091-go (Go): upgrade to 1.13.0 or later

  ```sh
  go get github.com/rabbitmq/amqp091-go@v1.13.0
  ```


## Technical details

The vulnerability exists in the readField function of the amqp091-go library, which parses AMQP frame data. When processing byte-array fields (type 'x'), the code reads a 32-bit signed integer to determine payload length and passes it directly to Go's make() function without validation. If a server sends a length value of 0xFFFFFFFF, it is interpreted as -1, causing make() to panic with "len out of range" since slice sizes must be non-negative. The panic occurs in the network I/O reader goroutine without recovery handling, terminating the entire host process. An attacker controlling or compromising the AMQP broker can inject malicious frames during connection establishment or message delivery to trigger this crash reliably.

## Affected products

- RabbitMQ amqp091-go <UNKNOWN>

## Identifiers

- CVE-2026-77412
- GHSA-4v58-74mf-rjx3
- GO-2026-6494

## Timeline

- 2026-09-17: disclosed

## Related threats

- [amqp091-go pre-negotiation frame limit bypass in connection reader](https://junglewise.ai/threats/cve-2026-107386-amqp091-go-pre-negotiation-frame-limit-is-not-enforced-to-4kb)
- [RabbitMQ amqp091-go protocol desynchronization via integer overflow](https://junglewise.ai/threats/cve-2026-77411-rabbitmq-amqp091-go-protocol-desynchronization-via-integer)
- [RabbitMQ amqp091-go resource exhaustion via unbounded buffer allocation](https://junglewise.ai/threats/cve-2026-77410-rabbitmq-amqp091-go-resource-exhaustion-via-unbounded-buffer)
- [RabbitMQ amqp091-go synchronous notification blocking](https://junglewise.ai/threats/cve-2026-77409-rabbitmq-amqp091-go-synchronous-notification-blocking)
- [RabbitMQ amqp091-go silent data truncation via shortstr integer overflow](https://junglewise.ai/threats/cve-2026-77408-rabbitmq-amqp091-go-silent-data-truncation-via-shortstr-integer)