Vulnerability · Published Aug 26, 2026 · Assigned by VulnCheck
CVE-2026-48548Nagios Core CSRF via cmd.cgi
Medium 6.5
In plain English
A medium-severity cross-site request forgery in Nagios Core from Nagios Enterprises, LLC.. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 12% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Nagios Core before 4.5.12 contains a cross-site request forgery vulnerability in cmd.cgi where the CSRF protection mechanism passes validation when the NagFormId cookie is absent. Attackers can craft a malicious cross-site POST request to execute arbitrary Nagios commands as a currently authenticated user without their knowledge or consent.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | nagios4 | 4.4.6-4+deb12u1 | DEBIAN-CVE-2026-48548 |
| Debian:13 | nagios4 | 4.4.6-4.1+deb13u1 | DEBIAN-CVE-2026-48548 |
| Debian:14 | nagios4 | 4.5.12+ds-1 | DEBIAN-CVE-2026-48548 |
| Ubuntu:22.04:LTS | nagios4 | no fix listed | UBUNTU-CVE-2026-48548 |
| Ubuntu:24.04:LTS | nagios4 | no fix listed | UBUNTU-CVE-2026-48548 |
| Ubuntu:26.04:LTS | nagios4 | no fix listed | UBUNTU-CVE-2026-48548 |
| Ubuntu:26.10 | nagios4 | no fix listed | UBUNTU-CVE-2026-48548 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Nagios Enterprises, LLC. | Nagios Core | 0 – before 4.5.12 |
Weakness: CWE-352 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
References
- Security Disclosures vendor-advisory, patch
- Changelog release-notes
- https://www.vulncheck.com/advisories/nagios-core-csrf-via-cmd-cgi third-party-advisory