What is CVE-2021-25296?

CVE-2021-25296 is a high-severity vulnerability in Nagios Xi. CVSS score: 8.8/10. Published 2021-02-15.

How severe is CVE-2021-25296?

High severity. CVSS v3 base score is 8.8 out of 10.

Is CVE-2021-25296 known to be exploited?

Yes. CVE-2021-25296 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2022-01-18), indicating it is being actively exploited. 10 public proof-of-concept repositories are indexed.

Vulnerability in Nagios Xi

CVE-2021-25296

Nagios XI version xi-5.7.5 is affected by OS command injection. The vulnerability exists in the file /usr/local/nagiosxi/html/includes/configwizards/windowswmi/windowswmi.inc.php due to improper sanitization of authenticated user-controlled input by a single HTTP request, which can lead to OS command injection on the Nagios XI server.

Published 2021-02-15 · last modified 2026-07-09.

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.719 (99.4th percentile), scored 2026-10-19.

High probability of exploitation in the next 30 days — patch promptly. 99th percentile — 99.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.722 · newest: 0.719 · change: -0.002

Affected products

Nagios Xi

CISA KEV (Known Exploited Vulnerabilities)

This CVE is on the CISA KEV catalog, added on 2022-01-18. CISA KEV inclusion means CISA has confirmed in-the-wild exploitation; US federal agencies are required to remediate within a published due date.

BOD 22-01 due date: 2022-02-01.

Required action: Apply updates per vendor instructions.

Public proof-of-concept exploits

References

af854a3a-2127-422b-91ae-364da2661108 (Product)
assets.nagios.com/downloads/nagiosxi/versions.php (Product, Exploit)
github.com/fs0c-sh/nagios-xi-5.7.5-bugs/blob/main/README.md (Exploit, Third Party Advisory)
packetstormsecurity.com/files/161561/Nagios-XI-5.7.5-Remote-Code-Execution.html (Exploit, VDB Entry, Third Party Advisory)
packetstormsecurity.com/files/170924/Nagios-XI-5.7.5-Remote-Code-Execution.html (VDB Entry, Third Party Advisory)
www.fastly.com/blog/anatomy-of-a-command-injection-cve-2021-25296-7-8-with-meta… (Exploit, Third Party Advisory)
134c704f-9b21-4f2e-91b3-4a467353bcc0 (US Government Resource)

Frequently asked questions

What is CVE-2021-25296?: CVE-2021-25296 is a high-severity vulnerability in Nagios Xi. CVSS score: 8.8/10. Published 2021-02-15.
How severe is CVE-2021-25296?: High severity. CVSS v3 base score is 8.8 out of 10.
Is CVE-2021-25296 known to be exploited?: Yes. CVE-2021-25296 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2022-01-18), indicating it is being actively exploited. 10 public proof-of-concept repositories are indexed.