CVE-2021-25298: Nagios XI OS Command Injection
- Is it exploited?
Yes. CISA added it to the Known Exploited Vulnerabilities catalog on 18 Jan 2022, 337 days after the CVE record was published.
- How likely is exploitation in the next 30 days?
- 73.6%
EPSS score, percentile 99.5 of all scored records
- How severe?
- 8.8 High
CVSS v3.1 base score, from CISA's enrichment of the record
- What should I do?
CISA deadline 1 Feb 2022. Apply updates per vendor instructions.
The CVE record links no vendor advisory, patch or mitigation.
- Which versions are affected?
Not stated. The CVE record gives vendor and product as “n/a” and the version as “unspecified”.
Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of 28 Oct 2026; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of 28 Oct 2026; CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026. About the data.
What to do
Required action, set by CISA
Apply updates per vendor instructions.
CISA due date for this action: 1 February 2022.
Advisories and patches
The CVE record links no vendor advisory, patch or mitigation.
Linked from CISA's catalog entry
Affected products and versions
The CVE record does not name affected products or versions: vendor and product are “n/a” and the version is “unspecified”.
Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026. About the data.
About this vulnerability
Nagios XI contains a vulnerability which can lead to OS command injection on the Nagios XI server.
Summary: CISA's KEV catalog, as of 28 Oct 2026.
- CISA added CVE-2021-25298 to its Known Exploited Vulnerabilities (KEV) catalog on 18 Jan 2022.
- CISA's ransomware flag for this entry is "Unknown": no evidence of ransomware use in the catalog, which is not proof of none.
- The due date CISA sets for the required action is 1 Feb 2022.
- The CVE record was published on 15 Feb 2021, 337 days before it was added to KEV.
- The CVE record carries a CVSS v3.1 base score of 8.8 (High), taken from CISA's enrichment of the record.
- FIRST's EPSS model puts the probability of exploitation in the next 30 days at 73.6% (percentile 99.5), as of 28 Oct 2026.
- CISA's SSVC assessment in the CVE record: exploitation active, automatable no, technical impact total.
Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of 28 Oct 2026; CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of 28 Oct 2026. About the data.
Description
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/cloud-vm/cloud-vm.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.
Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026. About the data.
Weakness
- CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
- CWE-138
CWE and CAPEC are maintained by MITRE; the entries are those named in the CVE record and the KEV entry.
Timeline
| Date | Event |
|---|---|
| 15 Feb 2021 | CVE record published |
| 18 Jan 2022 | Added to CISA KEV |
| 1 Feb 2022 | CISA due date for the required action |
| 9 Jul 2026 | CVE record last updated |
References
More exploited Nagios vulnerabilities
- CVE-2021-25296: Nagios XI OS Command Injection
- CVE-2021-25297: Nagios XI OS Command Injection
- CVE-2019-15949: Nagios XI Remote Code Execution Vulnerability