CVE-2025-64998

HIGH

Session hijacking via exposed session signing secret in distributed Checkmk setups

Title source: cna

Description

Exposure of session signing secret in Checkmk <2.4.0p23, <2.3.0p45 and 2.2.0 allows an administrator of a remote site with config sync enabled to hijack sessions on the central site by forging session cookies.

References (1)

[Vendor Advisory] https://checkmk.com/werk/18954

Scores

CVSS v4 7.3

EPSS 0.0005

EPSS Percentile 15.7%

CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

CISA SSVC

Vulnrichment

Exploitation none

Automatable no

Technical Impact total

Details

CWE

CWE-522

Status published

Products (3)

Checkmk GmbH/Checkmk 2.2.0

Checkmk GmbH/Checkmk 2.3.0 - 2.3.0p45

Checkmk GmbH/Checkmk 2.4.0 - 2.4.0p23

Published Mar 24, 2026

Tracked Since Mar 24, 2026