Description
Nagios Core before 4.5.14 and Nagios XI before 2026R1.7 are vulnerable to DOM-based cross-site scripting in jsonquery.js. Unencoded JSON string values reflected from stored fields are inserted into the DOM without sanitization, allowing attackers to run arbitrary JavaScript in the victim's browser.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Nagios Enterprises, LLC. | Nagios Core | < 4.5.14 | 4.5.14 |
| Nagios Enterprises, LLC. | Nagios XI | < 2026R1.7 | 2026R1.7 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | nagios4 | 4.5.14+ds-1 | — |
| Debian 13 | nagios4 | 4.4.6-4.1+deb13u2 | — |
| Debian 12 | nagios4 | 4.4.6-4+deb12u2 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | nagios4 | No fix yet | — |
| Ubuntu 26.04 LTS | nagios4 | No fix yet | — |
| Ubuntu 24.04 LTS | nagios4 | No fix yet | — |
| Ubuntu 22.04 LTS | nagios4 | No fix yet | — |
| Ubuntu 20.04 LTS | nagios4 | No fix yet | — |
Advisories 1
- WID-SEC-2026-2819 Nagios Core und Nagios XI: Mehrere Schwachstellen BSI CERT-Bund (WID) · Oct 12, 2026
References
- Security Disclosures vendor-advisory patch
- Changelog release-notes
- https://www.vulncheck.com/advisories/nagios-core-xi-dom-based-xss-via-jsonquery-js third-party-advisory