CVE-2025-64998: Session hijacking via exposed session signing secret in distributed Checkmk setups
Published Mar 24, 2026
·Updated
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.
Affected Software
138 affected components
Tribe29 Checkmk<2.4.0p23, <2.3.0p45, =2.2.0
Checkmk Checkmk=2.2.0
Checkmk Checkmk=2.2.0-b1
Checkmk Checkmk=2.2.0-b2
Checkmk Checkmk=2.2.0-b3
Checkmk Checkmk=2.2.0-b4
Checkmk Checkmk=2.2.0-b5
Checkmk Checkmk=2.2.0-b6
Checkmk Checkmk=2.2.0-b7
Checkmk Checkmk=2.2.0-b8
Checkmk Checkmk=2.2.0-i1
Checkmk Checkmk=2.2.0-p1
Checkmk Checkmk=2.2.0-p10
Checkmk Checkmk=2.2.0-p11
Checkmk Checkmk=2.2.0-p12
Checkmk Checkmk=2.2.0-p13
Checkmk Checkmk=2.2.0-p14
Checkmk Checkmk=2.2.0-p15
Checkmk Checkmk=2.2.0-p16
Checkmk Checkmk=2.2.0-p17
Checkmk Checkmk=2.2.0-p18
Checkmk Checkmk=2.2.0-p19
Checkmk Checkmk=2.2.0-p2
Checkmk Checkmk=2.2.0-p20
Checkmk Checkmk=2.2.0-p21
Checkmk Checkmk=2.2.0-p22
Checkmk Checkmk=2.2.0-p23
Checkmk Checkmk=2.2.0-p24
Checkmk Checkmk=2.2.0-p25
Checkmk Checkmk=2.2.0-p26
Checkmk Checkmk=2.2.0-p27
Checkmk Checkmk=2.2.0-p28
Checkmk Checkmk=2.2.0-p29
Checkmk Checkmk=2.2.0-p3
Checkmk Checkmk=2.2.0-p30
Checkmk Checkmk=2.2.0-p31
Checkmk Checkmk=2.2.0-p32
Checkmk Checkmk=2.2.0-p33
Checkmk Checkmk=2.2.0-p34
Checkmk Checkmk=2.2.0-p35
Checkmk Checkmk=2.2.0-p36
Checkmk Checkmk=2.2.0-p37
Checkmk Checkmk=2.2.0-p38
Checkmk Checkmk=2.2.0-p39
Checkmk Checkmk=2.2.0-p4
Checkmk Checkmk=2.2.0-p40
Checkmk Checkmk=2.2.0-p41
Checkmk Checkmk=2.2.0-p42
Checkmk Checkmk=2.2.0-p43
Checkmk Checkmk=2.2.0-p44
Checkmk Checkmk=2.2.0-p45
Checkmk Checkmk=2.2.0-p46
Checkmk Checkmk=2.2.0-p47
Checkmk Checkmk=2.2.0-p5
Checkmk Checkmk=2.2.0-p6
Checkmk Checkmk=2.2.0-p7
Checkmk Checkmk=2.2.0-p8
Checkmk Checkmk=2.2.0-p9
Checkmk Checkmk=2.3.0
Checkmk Checkmk=2.3.0-b1
Checkmk Checkmk=2.3.0-b2
Checkmk Checkmk=2.3.0-b3
Checkmk Checkmk=2.3.0-b4
Checkmk Checkmk=2.3.0-b5
Checkmk Checkmk=2.3.0-b6
Checkmk Checkmk=2.3.0-p1
Checkmk Checkmk=2.3.0-p10
Checkmk Checkmk=2.3.0-p11
Checkmk Checkmk=2.3.0-p12
Checkmk Checkmk=2.3.0-p13
Checkmk Checkmk=2.3.0-p14
Checkmk Checkmk=2.3.0-p15
Checkmk Checkmk=2.3.0-p16
Checkmk Checkmk=2.3.0-p17
Checkmk Checkmk=2.3.0-p18
Checkmk Checkmk=2.3.0-p19
Checkmk Checkmk=2.3.0-p2
Checkmk Checkmk=2.3.0-p20
Checkmk Checkmk=2.3.0-p21
Checkmk Checkmk=2.3.0-p22
Checkmk Checkmk=2.3.0-p23
Checkmk Checkmk=2.3.0-p24
Checkmk Checkmk=2.3.0-p25
Checkmk Checkmk=2.3.0-p26
Checkmk Checkmk=2.3.0-p27
Checkmk Checkmk=2.3.0-p28
Checkmk Checkmk=2.3.0-p29
Checkmk Checkmk=2.3.0-p3
Checkmk Checkmk=2.3.0-p30
Checkmk Checkmk=2.3.0-p31
Checkmk Checkmk=2.3.0-p32
Checkmk Checkmk=2.3.0-p33
Checkmk Checkmk=2.3.0-p34
Checkmk Checkmk=2.3.0-p35
Checkmk Checkmk=2.3.0-p36
Checkmk Checkmk=2.3.0-p37
Checkmk Checkmk=2.3.0-p38
Checkmk Checkmk=2.3.0-p39
Checkmk Checkmk=2.3.0-p4
Checkmk Checkmk=2.3.0-p40
Checkmk Checkmk=2.3.0-p41
Checkmk Checkmk=2.3.0-p42
Checkmk Checkmk=2.3.0-p43
Checkmk Checkmk=2.3.0-p44
Checkmk Checkmk=2.3.0-p5
Checkmk Checkmk=2.3.0-p6
Checkmk Checkmk=2.3.0-p7
Checkmk Checkmk=2.3.0-p8
Checkmk Checkmk=2.3.0-p9
Checkmk Checkmk=2.4.0
Checkmk Checkmk=2.4.0-b1
Checkmk Checkmk=2.4.0-b2
Checkmk Checkmk=2.4.0-b3
Checkmk Checkmk=2.4.0-b4
Checkmk Checkmk=2.4.0-b5
Checkmk Checkmk=2.4.0-b6
Checkmk Checkmk=2.4.0-p1
Checkmk Checkmk=2.4.0-p10
Checkmk Checkmk=2.4.0-p11
Checkmk Checkmk=2.4.0-p12
Checkmk Checkmk=2.4.0-p13
Checkmk Checkmk=2.4.0-p14
Checkmk Checkmk=2.4.0-p15
Checkmk Checkmk=2.4.0-p16
Checkmk Checkmk=2.4.0-p17
Checkmk Checkmk=2.4.0-p18
Checkmk Checkmk=2.4.0-p19
Checkmk Checkmk=2.4.0-p2
Checkmk Checkmk=2.4.0-p20
Checkmk Checkmk=2.4.0-p21
Checkmk Checkmk=2.4.0-p22
Checkmk Checkmk=2.4.0-p3
Checkmk Checkmk=2.4.0-p4
Checkmk Checkmk=2.4.0-p5
Checkmk Checkmk=2.4.0-p6
Checkmk Checkmk=2.4.0-p7
Checkmk Checkmk=2.4.0-p8
Checkmk Checkmk=2.4.0-p9
Event History
Mar 24, 2026
CVE Published
via MITRE·11:25 AM
Data Sourced
via MITRE·11:25 AM
DescriptionWeakness
Data Sourced
via NVD·12:16 PM
DescriptionSeverityWeaknessAffected Software
Frequently Asked Questions
1
What is the severity of CVE-2025-64998?
CVE-2025-64998 has a high severity rating due to the potential for session hijacking.
2
How do I fix CVE-2025-64998?
To fix CVE-2025-64998, upgrade to Checkmk version 2.4.0p23 or later, 2.3.0p45 or later, or 2.2.1 and above.
3
Who is affected by CVE-2025-64998?
CVE-2025-64998 affects administrators of Checkmk setups running vulnerable versions with config sync enabled.
4
What are the risks of CVE-2025-64998?
The primary risk of CVE-2025-64998 is the ability for malicious users to hijack sessions, potentially leading to unauthorized access.
5
How can I verify if my Checkmk instance is vulnerable to CVE-2025-64998?
You can verify vulnerability by checking if your Checkmk version is earlier than 2.4.0p23, 2.3.0p45, or exactly 2.2.0.