CVE-2021-38156

MEDIUMNVD 5.45.4—Elevated

5.4

In Nagios XI before 5.8.6, XSS exists in the dashboard page (/dashboards/#) when administrative users attempt to edit a dashboard.

CVSS v3: 5.4
EG Score: 5.4(medium)
EPSS: 99.3%
KEV: Not listed

Published

September 15, 2021

Last Modified

November 21, 2024

References (4)

cve@mitrehttps://raxis.com/blog/cve-2021-38156
cve@mitrehttps://www.nagios.com/downloads/nagios-xi/change-log/
af854a3a-2127-422b-91ae-364da2661108https://raxis.com/blog/cve-2021-38156
af854a3a-2127-422b-91ae-364da2661108https://www.nagios.com/downloads/nagios-xi/change-log/

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

CWE-79Cross-site Scripting (XSS)

Data Freshness Timeline

(refreshed 6× in last 7d / 15× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

2026-06-06 13:46 UTCEPSS rescore
2026-06-06 13:46 UTCEPSS rescore
2026-06-06 13:46 UTCEPSS rescore
2026-06-05 22:45 UTCEPSS rescore
2026-06-04 13:10 UTCEPSS rescore
2026-06-04 13:10 UTCEPSS rescore
2026-06-01 13:50 UTCEPSS rescore
2026-06-01 13:50 UTCEPSS rescore
2026-05-31 00:15 UTCEPSS rescore
2026-05-31 00:15 UTCEPSS rescore
2026-05-28 13:43 UTCEPSS rescore
2026-05-28 13:43 UTCEPSS rescore
2026-05-26 10:21 UTCEG score recompute
2026-05-26 10:21 UTCGHSA enrichment
2026-05-23 12:11 UTCOSV refresh

Publicly available exploits

(1 reference)

Working exploit code is in the public domain. Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

Nucleihttp/cves/2021/CVE-2021-38156.yaml
First seen Jan 1, 2021
Nagios XI < 5.8.6 - Cross-Site Scripting
Open source ↗

Frequently asked(5)

What is CVE-2021-38156?

CVE-2021-38156 is a medium vulnerability published on September 15, 2021. In Nagios XI before 5.8.6, XSS exists in the dashboard page (/dashboards/#) when administrative users attempt to edit a dashboard.

When was CVE-2021-38156 disclosed?

CVE-2021-38156 was first published in the National Vulnerability Database on September 15, 2021, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.

Is CVE-2021-38156 actively exploited?

CVE-2021-38156 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 99.3% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.

What is the CVSS score of CVE-2021-38156?

CVE-2021-38156 has a CVSS v3 base score of 5.4 (NVD).

How do I remediate CVE-2021-38156?

Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-38156, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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CVE-2021-38156

📅 Published

🔄 Last Modified

🔗 References (4)

Weakness Classification(1)

Data Freshness Timeline

Publicly available exploits

❓ Frequently asked(5)

Dependency Blast Radius

Is Your Infrastructure Affected by CVE-2021-38156?

🔗 Related CVEs(same CWE)

Same CWE

Published

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References (4)

Frequently asked(5)

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