CVE-2026-48548

Nagios Core CSRF via cmd.cgi

6.9 MediumFix available

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.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: Low
Privileges needed: None
User interaction: Active

What an attacker can affect

Confidentiality: None
Integrity: High
Availability: None

Exploit likelihood

0.21%Up 0.1 points since Aug 27, 2026

What each source reports

CVE List Score used 6.9

Nagios Core CSRF via cmd.cgi

Record: CVE-2026-48548
CVSS 4.0: 6.9 MediumCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
CVSS 3.1: 6.5 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
Weakness: CWE-352
Updated: 2026-11-02

EUVDEUVD-2026-66598 6.9

Record: EUVD-2026-66598
CVSS 4.0: 6.9 MediumCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
Updated: 2026-11-02

GitHub AdvisoriesGHSA-5xj4-4632-2x3r 6.9

Nagios Core before 4.5.12 contains a cross-site request forgery vulnerability in cmd.cgi where...

Record: GHSA-5xj4-4632-2x3r
CVSS 4.0: 6.9 MediumCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS 3.1: 6.5 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
Weakness: CWE-352
Updated: 2026-11-02

NVD 6.9

Record: CVE-2026-48548
CVSS 4.0: 6.9 MediumCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS 3.1: 6.5 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
Weakness: CWE-352
Updated: 2026-11-02

OSV 6.9

Nagios Core CSRF via cmd.cgi

Record: CVE-2026-48548
CVSS 4.0: 6.9 MediumCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
Weakness: CWE-352
Updated: 2026-11-02

OSVDEBIAN-CVE-2026-48548 6.9

Record: DEBIAN-CVE-2026-48548
CVSS 4.0: 6.9 MediumCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Updated: 2026-11-02

OSVUBUNTU-CVE-2026-48548 6.9

Record: UBUNTU-CVE-2026-48548
CVSS 4.0: 6.9 MediumCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
CVSS 3.1: 6.5 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
Updated: 2026-11-02

Affected products

Affected packages

Affected packages
Package	Affected	Fixed
`nagios4` Debian:12	before 4.4.6-4+deb12u1, plus listed versions 4.4.6-4	4.4.6-4+deb12u1
`nagios4` Debian:13	before 4.4.6-4.1+deb13u1, plus listed versions 4.4.6-4.1	4.4.6-4.1+deb13u1
`nagios4` Debian:14	before 4.5.12+ds-1, plus listed versions 4.4.6-4.1	4.5.12+ds-1
`nagios4` Ubuntu:20.04:LTS	All versions, plus listed versions 4.3.4-34.3.4-3ubuntu0.1	None known
`nagios4` Ubuntu:22.04:LTS	All versions, plus listed versions 4.4.6-44.4.6-4ubuntu0.22.04.1	None known
`nagios4` Ubuntu:24.04:LTS	All versions, plus listed versions 4.4.6-44.4.6-4ubuntu0.24.04.1	None known
`nagios4` Ubuntu:26.10	All versions, plus listed versions 4.4.6-4.1ubuntu2	None known
`nagios4` Ubuntu:26.04:LTS	All versions, plus listed versions 4.4.6-4.1ubuntu14.4.6-4.1ubuntu2	None known

History

History
Recorded	Changed	Sources
Nov 2, 2026	first indexed	CVE List, EUVD, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2026-48548 is a medium vulnerability (CVSS 6.9) in Nagios Enterprises, Llc. Core, published August 26, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.21%, the 11th percentile. Fixed in nagios4 4.4.6-4+deb12u1.