What is CVE-2021-36756?

CVE-2021-36756 is a medium-severity vulnerability in Northern.tech Cfengine, classified under Improper Certificate Validation. CVSS score: 6.5/10. Published 2021-10-27.

How severe is CVE-2021-36756?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Vulnerability in Northern.tech Cfengine

CVE-2021-36756

CFEngine Enterprise 3.15.0 through 3.15.4 has Missing SSL Certificate Validation.

Vulnerability class: Improper Certificate Validation

Published 2021-10-27 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.004 (33.5th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 33rd percentile — 33.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000

Affected products

Northern.tech Cfengine

Weakness classification (CWE)

CWE-295 — Improper Certificate Validation

References

cfengine.com/downloads/cfengine-enterprise/ (Patch, Vendor Advisory)
cfengine.com/blog/2021/cve-2021-38379-and-cve-2021-36756/ (Patch, Vendor Advisory)

Frequently asked questions

What is CVE-2021-36756?: CVE-2021-36756 is a medium-severity vulnerability in Northern.tech Cfengine, classified under Improper Certificate Validation. CVSS score: 6.5/10. Published 2021-10-27.
How severe is CVE-2021-36756?: Medium severity. CVSS v3 base score is 6.5 out of 10.