What is CVE-2021-36365?

CVE-2021-36365 is a critical-severity vulnerability in Nagios Xi, classified under Incorrect Default Permissions. CVSS score: 9.8/10. Published 2021-09-28.

How severe is CVE-2021-36365?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Vulnerability in Nagios Xi

CVE-2021-36365

Nagios XI before 5.8.5 has Incorrect Permission Assignment for repairmysql.sh.

Published 2021-09-28 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.038 (89.6th percentile), scored 2026-09-29.

Low probability of exploitation in the next 30 days, but still tracked. 90th percentile — 89.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.038 · newest: 0.038 · change: 0.000

Affected products

Nagios Xi

Weakness classification (CWE)

CWE-276 — Incorrect Default Permissions

References

www.nagios.com/downloads/nagios-xi/change-log/ (Release Notes, Vendor Advisory)
assets.nagios.com/downloads/nagiosxi/CHANGES-5.TXT (Release Notes, Vendor Advisory)

Frequently asked questions

What is CVE-2021-36365?: CVE-2021-36365 is a critical-severity vulnerability in Nagios Xi, classified under Incorrect Default Permissions. CVSS score: 9.8/10. Published 2021-09-28.
How severe is CVE-2021-36365?: Critical severity. CVSS v3 base score is 9.8 out of 10.