---
id: CVE-2018-19653
aliases:
  - GHSA-4qvx-qq5w-695p
  - GO-2023-1850
title: HashiCorp Consul can use cleartext agent-to-agent RPC communication
summary: HashiCorp Consul can use cleartext agent-to-agent RPC communication
severity: medium
cvss: 5.9
cvssVector: 'CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N'
vendor: hashicorp
product: github.com/hashicorp/consul
ecosystem: go
affected:
  - 'github.com/hashicorp/consul >= 0.5.1, < 1.4.1'
patched:
  - github.com/hashicorp/consul 1.4.1
published: '2022-05-14'
updated: '2026-09-10'
sourceUpdated: '2026-09-10T03:49:37.495348649Z'
source: OSV
sourceUrl: 'https://osv.dev/vulnerability/GHSA-4qvx-qq5w-695p'
references:
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2018-19653'
  - url: 'https://github.com/hashicorp/consul/pull/5069'
  - url: >-
      https://github.com/hashicorp/consul/commit/b64e8b262f80397eab4f39c6ae7e14683cb9f55c
  - url: 'https://github.com/hashicorp/consul'
  - url: 'https://groups.google.com/forum/#!topic/consul-tool/7TCw06oio0I'
tags:
  - osv
  - go
epss: 0.01165
epssPercentile: 0.65448
ingestedAt: '2026-09-12T03:13:01.753Z'
---

## Overview

HashiCorp Consul 0.5.1 through 1.4.0 can use cleartext agent-to-agent RPC communication because the `verify_outgoing` setting is improperly documented. NOTE: the vendor has provided reconfiguration steps that do not require a software upgrade.

## Affected packages

- `github.com/hashicorp/consul >= 0.5.1, < 1.4.1`

## Remediation

Upgrade to a patched release:

- `github.com/hashicorp/consul 1.4.1`