RabbitMQ amqp091-go: Missing Explicit TLS Minimum Version Configuration In URI Parser

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

9.4 · CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:H/SI:L/SA:N · score source

EPSS

• CVE-2026-77405: 0.28% estimated exploitation activity in the next 30 days; percentile 20.76 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary A structural security weakness exists in the AMQP client's TLS configuration generator (tlsConfigFromURI). When constructing a tls.Config object from an amqps:// connection URI, the library initializes the structure without explicitly defining the MinVersion field. While modern versions of the Go compiler toolchain (Go 1.18+) default the implicit minimum version to TLS 1.2, this security posture relies entirely on an implicit toolchain dependency. If the library is compiled using legacy Go toolchains (Go < 1.18), or if a future toolchain introduces fallback behavior, the client could silently negotiate obsolete and insecure TLS 1.0 or TLS 1.1 protocols during connection handshakes with a compromised or malicious AMQP broker. --- Vulnerability Details Mechanism The vulnerability lies in the lack of an explicit safety floor when assigning configurations inside the URI component: In the Go standard library (crypto/tls), leaving MinVersion: 0 instructs the runtime to choose the…

Published by the source

17 Sep 2026, 17:04 UTC

Last modified by the source

1 Oct 2026, 20:45 UTC

Source last checked

26 Oct 2026, 15:29 UTC

1. Revision 4 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-33mj-cw25-m34h

2. Revision 3 · amended · 25 Oct 2026

   Reviewed OSV alias/range/CVSS4 correction; package source scopes and original publication preserved. No customer finding resolved.

3. Revision 2 · amended · 24 Oct 2026

   Amended from osv record GO-2026-6492

4. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-33mj-cw25-m34h

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# Patch Next advisory brief: CVE-2026-77405

Advisory: RabbitMQ amqp091-go: Missing Explicit TLS Minimum Version Configuration In URI Parser
IDs: CVE-2026-77405, GHSA-33mj-cw25-m34h
Record: https://patchnext.com/advisories/cve-2026-77405 (revision 4, source checked 26 Oct 2026, 15:29 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Critical (CVSS 9.4)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/rabbitmq/amqp091-go 1.13.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/rabbitmq/amqp091-go: affected < 1.13.0; fixed in 1.13.0

## Suggested inspection (read-only)
- Go github.com/rabbitmq/amqp091-go: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/rabbitmq/amqp091-go.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-33mj-cw25-m34h (OSV record GHSA-33mj-cw25-m34h lists affected ranges: Go github.com/rabbitmq/amqp091-go >=0 <1.13.0 (fixed))
- Verified: https://osv.dev/vulnerability/GO-2026-6492 (OSV record GO-2026-6492 lists affected ranges: Go github.com/rabbitmq/amqp091-go >=0 <1.13.0 (fixed))
- Verified: https://github.com/advisories/GHSA-33mj-cw25-m34h (GitHub-reviewed advisory GHSA-33mj-cw25-m34h lists affected ranges: Go github.com/rabbitmq/amqp091-go >=0 <1.13.0)

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