Session Hijacking Vulnerability in Checkmk by tribe29
CVE-2025-64998

7.3HIGH

Key Information:

Vendor

Checkmk Gmbh

Status
Checkmk
Vendor
CVE Published:
24 March 2026

What is CVE-2025-64998?

A security flaw exists in Checkmk, where an exposure of the session signing secret allows an administrator from a remote site with config sync enabled to manipulate and hijack sessions on the central site by forging session cookies. This vulnerability poses a significant risk, enabling unauthorized access to sensitive information.

Affected Version(s)

Checkmk 2.4.0 < 2.4.0p23

Checkmk 2.3.0 < 2.3.0p45

Checkmk 2.2.0

References

https://checkmk.com/werk/18954
vendor-advisory

CVSS V4

Score:
7.3
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
Physical
Privileges Required:
Undefined
User Interaction:
Unknown

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Lisa Gnedt (SBA Research)
.