What is CVE-2020-15336?

CVE-2020-15336 is a high-severity vulnerability in Zyxel Cloudcnm Secumanager, classified under Missing Authentication for Critical Function. CVSS score: 7.5/10. Published 2020-06-26.

How severe is CVE-2020-15336?

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

Auth bypass in Zyxel Cloudcnm Secumanager

CVE-2020-15336

Zyxel CloudCNM SecuManager 3.1.0 and 3.1.1 has no authentication for /cnr requests.

Vulnerability class: Broken Authentication

Published 2020-06-26 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N.

EPSS exploit prediction

EPSS: 0.009 (59.4th percentile), scored 2026-10-03.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 59th percentile — 59.4% 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

Zyxel Cloudcnm Secumanager — versions 3.1.0, 3.1.1

Weakness classification (CWE)

CWE-306 — Missing Authentication for Critical Function

References

www.zyxel.com/support/vulnerabilities-of-CloudCNM-SecuManager.shtml (Vendor Advisory)
pierrekim.github.io/blog/2020-03-09-zyxel-secumanager-0day-vulnerabilities.html (Third Party Advisory)

Frequently asked questions

What is CVE-2020-15336?: CVE-2020-15336 is a high-severity vulnerability in Zyxel Cloudcnm Secumanager, classified under Missing Authentication for Critical Function. CVSS score: 7.5/10. Published 2020-06-26.
How severe is CVE-2020-15336?: High severity. CVSS v3 base score is 7.5 out of 10.