CVE-2024-13993

Nagios XI versions prior to < 2024R1.1.2 are vulnerable to a reflected cross-site scripting (XSS) via the login page when accessed with older web browsers. Insufficient validation or escaping of user-supplied input reflected by the login page can allow an attacker to craft a malicious link that, when visited by a victim, executes arbitrary JavaScript in the victim’s browser within the Nagios XI origin. The issue is observable under legacy browser behaviors; modern browsers may mitigate some vectors.

CVSS 4.0

5.1CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N

CVSS 3.1

6.1CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

EPSS

0.8% chance of exploitation in the next 30 days; higher than 56% of CVEs (scores of 2026-10-25)

CWE

CWE-79

Published

2025-10-30

Modified

2026-10-02

Record from

the NVD, synced 2026-10-19

Affected

• nagios:nagios_xi

References

• https://www.nagios.com/changelog/nagios-xi/
• https://www.nagios.com/products/security/#nagios-xi
• https://www.vulncheck.com/advisories/nagios-xi-reflected-xss-via-login-page-on-older-browsers

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