CVE-2026-48551

HIGH 7.4

Nagios Core / XI CSRF Protection Bypass via Double-Submit Cookie

CVSS Score

7.4

EPSS Score

0.0%

EPSS Percentile

0th

Nagios Core before 4.5.14 and Nagios XI before 2026R1.7 contain a cross-site request forgery protection bypass via a self-supplied double-submit cookie. An attacker can supply matching cookie and request parameter values to bypass CSRF protection, enabling unauthenticated attackers to run commands as authorized users via malicious links.

CWE	CWE-352
Vendor	nagios enterprises, llc.
Product	nagios core
Published	Aug 12, 2026

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CVSS v3 Breakdown

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

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Changed

Confidentiality

None

Integrity

High

Availability

None

Affected Versions

Nagios Enterprises, LLC. / Nagios Core

0 < 4.5.14

Nagios Enterprises, LLC. / Nagios XI

0 < 2026R1.7

References

NVD ↗ CVE.org ↗ EPSS Data ↗

nagios.com: https://www.nagios.com/security-disclosures/nagios-core/ github.com: https://github.com/NagiosEnterprises/nagioscore/blob/master/Changelog vulncheck.com: https://www.vulncheck.com/advisories/nagios-core-xi-csrf-protection-bypass-via-double-submit-cookie

Credits

Zach Hanley of Horizon3.ai