What’s Vulnerable › Vulnerabilities

CVE-2021-35478

• Severity: medium (CVSS 5.4 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 76.6% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2021-07-30 · updated 2026-06-17
• Weakness: CWE-79

Description

Nagios Log Server before 2.1.9 contains Reflected XSS in the dropdown box for the alert history and audit log function. All parameters used for filtering are affected. This affects users who open a crafted link or third-party web page.

Affected products

• Nagios Log Server: before 2.1.9 — fixed in 2.1.9

How to fix

Upgrade to a fixed version: Nagios Log Server 2.1.9. Check the vendor advisory for mitigations.

References

• https://research.nccgroup.com/2021/07/22/technical-advisory-stored-and-reflected-xss-vulnerability-in-nagios-log-server-cve-2021-35478cve-2021-35479/
• https://research.nccgroup.com/?research=Technical%20advisories
• https://www.nagios.com/downloads/nagios-log-server/change-log/
• https://research.nccgroup.com/2021/07/22/technical-advisory-stored-and-reflected-xss-vulnerability-in-nagios-log-server-cve-2021-35478cve-2021-35479/
• https://research.nccgroup.com/?research=Technical%20advisories
• https://www.nagios.com/downloads/nagios-log-server/change-log/

Get alerted when CVE-2021-35478 or the next vulnerability affects your stack