CVE-2018-19653

HashiCorp Consul can use cleartext agent-to-agent RPC communication

5.9 MediumFix available

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.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: High
Privileges needed: None
User interaction: None

What an attacker can affect

Confidentiality: High
Integrity: None
Availability: None

Exploit likelihood

1.22%Up 0.6 points since Apr 14, 2021

What each source reports

NVD Score used 5.9

Record: CVE-2018-19653
CVSS 3.0: 5.9 MediumCVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
CVSS 2.0: 4.3 MediumAV:N/AC:M/Au:N/C:P/I:N/A:N
Weakness: CWE-310
Updated: 2026-11-02

CVE List No score

Record: CVE-2018-19653
Updated: 2026-11-02

EUVDEUVD-2022-2433 No score

Record: EUVD-2022-2433
Updated: 2026-11-03

GitHub AdvisoriesGHSA-4qvx-qq5w-695p 5.9

HashiCorp Consul can use cleartext agent-to-agent RPC communication

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.

Record: GHSA-4qvx-qq5w-695p
CVSS 3.0: 5.9 MediumCVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
Updated: 2026-11-02

OSV 5.9

Record: CVE-2018-19653
CVSS 3.0: 5.9 MediumCVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
Updated: 2026-11-02

OSVDEBIAN-CVE-2018-19653 5.9

Record: DEBIAN-CVE-2018-19653
CVSS 3.0: 5.9 MediumCVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
Updated: 2026-11-02

OSVGHSA-4qvx-qq5w-695p 5.9

HashiCorp Consul can use cleartext agent-to-agent RPC communication

Record: GHSA-4qvx-qq5w-695p
CVSS 3.0: 5.9 MediumCVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
Updated: 2026-11-02

OSVUBUNTU-CVE-2018-19653 5.9

Record: UBUNTU-CVE-2018-19653
CVSS 3.0: 5.9 MediumCVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
Updated: 2026-11-02

OSVGO-2023-1850 No score

HashiCorp Consul can use cleartext agent-to-agent RPC communication in github.com/hashicorp/consul

HashiCorp Consul can use cleartext agent-to-agent RPC communication in github.com/hashicorp/consul

Record: GO-2023-1850
Updated: 2026-11-02

Affected products

hashicorp consul

Affected packages

Affected packages
Package	Affected	Fixed
`github.com/hashicorp/consul` Go	0.5.1 up to 1.4.1	1.4.1
`consul` Debian:11	before 1.4.4~dfsg1-1	1.4.4~dfsg1-1
`consul` Ubuntu:18.04:LTS	All versions, plus listed versions 0.6.4~dfsg-3	None known

History

History
Recorded	Changed	Sources
Nov 3, 2026	aliases	EUVD
Nov 2, 2026	first indexed	CVE List, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2018-19653 is a medium vulnerability (CVSS 5.9) in Hashicorp Consul, published December 9, 2018. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.22%, the 68th percentile. Fixed in github.com/hashicorp/consul 1.4.1.