What is CVE-2021-37351?

CVE-2021-37351 is a medium-severity vulnerability in Nagios Xi, classified under Incorrect Default Permissions. CVSS score: 5.3/10. Published 2021-08-13.

How severe is CVE-2021-37351?

Medium severity. CVSS v3 base score is 5.3 out of 10.

Vulnerability in Nagios Xi

CVE-2021-37351

Nagios XI before version 5.8.5 is vulnerable to insecure permissions and allows unauthenticated users to access guarded pages through a crafted HTTP request to the server.

Published 2021-08-13 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N.

EPSS exploit prediction

EPSS: 0.028 (86.1th percentile), scored 2026-09-30.

Low probability of exploitation in the next 30 days, but still tracked. 86th percentile — 86.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.028 · newest: 0.028 · 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)

Frequently asked questions

What is CVE-2021-37351?: CVE-2021-37351 is a medium-severity vulnerability in Nagios Xi, classified under Incorrect Default Permissions. CVSS score: 5.3/10. Published 2021-08-13.
How severe is CVE-2021-37351?: Medium severity. CVSS v3 base score is 5.3 out of 10.