CSRF Protection Bypass in Nagios Core and Nagios XI
CVE-2026-48551

6.1MEDIUM

Key Information:

Vendor

NagiOS Enterprises, Llc.

Status
NagiOS Core
NagiOS Xi
Vendor
CVE Published:
12 August 2026

What is CVE-2026-48551?

Nagios Core and Nagios XI are vulnerable to a CSRF protection bypass due to an issue involving a double-submit cookie mechanism. An attacker can exploit this vulnerability by crafting malicious links that leverage a self-supplied cookie and corresponding request parameters. This allows unauthenticated attackers to execute commands on behalf of legitimate users, posing a significant risk to the integrity and security of systems using these products.

Affected Version(s)

Nagios Core 0

Nagios XI 0

References

https://www.nagios.com/security-disclosures/nagios-core/
vendor-advisorypatch
https://github.com/NagiosEnterprises/nagioscore/blob/mast...
release-notes
https://www.vulncheck.com/advisories/nagios-core-xi-csrf-...
third-party-advisory

CVSS V4

Score:
6.1
Severity:
MEDIUM
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
Unknown

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Zach Hanley of Horizon3.ai
.