What is CVE-2018-6517?

CVE-2018-6517 is a high-severity vulnerability in Puppet Chloride, classified under Improper Certificate Validation. CVSS score: 7.5/10. Published 2019-03-21.

How severe is CVE-2018-6517?

High severity. CVSS v3 base score is 7.5 out of 10.

Vulnerability in Puppet Chloride

CVE-2018-6517

Prior to version 0.3.0, chloride's use of net-ssh resulted in host fingerprints for previously unknown hosts getting added to the user's known_hosts file without confirmation. In version 0.3.0 this is updated so that the user's known_hosts file is not updated by chloride.

Vulnerability class: Improper Certificate Validation

Published 2019-03-21 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N.

EPSS exploit prediction

EPSS: 0.009 (57.9th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 58th percentile — 57.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.009 · newest: 0.009 · change: 0.000

Affected products

Puppet Chloride — versions prior to 0.3.0

Weakness classification (CWE)

CWE-295 — Improper Certificate Validation

References

puppet.com/security/cve/CVE-2018-6517 (Third Party Advisory)

Frequently asked questions

What is CVE-2018-6517?: CVE-2018-6517 is a high-severity vulnerability in Puppet Chloride, classified under Improper Certificate Validation. CVSS score: 7.5/10. Published 2019-03-21.
How severe is CVE-2018-6517?: High severity. CVSS v3 base score is 7.5 out of 10.