What is the CVSS score of CVE-2026-2859?

CVE-2026-2859 has a CVSS 3.1 base score of 4.3 (Medium). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N. EPSS exploitation probability: 0.1%.

Which versions of Checkmk are affected by CVE-2026-2859?

Organizations using Checkmk should be aware of moderate risk from CVE-2026-2859 rated CVSS 4.3. Exploitation could compromise the security of affected deployments.. A patch is available.

Checkmk CVE-2026-2859

EUVD-2026-11784 MEDIUM

Observable Response Discrepancy (CWE-204)

2026-03-13 Checkmk

Information Disclosure Checkmk

4.3

CVSS 3.1

CVSS VectorNVD

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

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

None

Availability

None

Lifecycle Timeline

Patch available

Apr 16, 2026 - 05:29 EUVD

2.3.0p43,2.4.0p23

EUVD ID Assigned

Mar 13, 2026 - 10:00 euvd

EUVD-2026-11784

Analysis Generated

Mar 13, 2026 - 10:00 vuln.today

CVE Published

Mar 13, 2026 - 09:40 nvd

MEDIUM 4.3

DescriptionNVD

Improper permission enforcement in Checkmk versions 2.4.0 before 2.4.0p23, 2.3.0 before 2.3.0p43, and 2.2.0 (EOL) allows unauthenticated users to enumerate existing hosts by observing different HTTP response codes in deploy_agent endpoint, which could lead to information disclosure.

AnalysisAI

Checkmk contains an improper permission enforcement vulnerability in the deploy_agent endpoint that allows unauthenticated users to enumerate existing hosts by analyzing differential HTTP response codes, resulting in information disclosure. The vulnerability affects Checkmk versions 2.4.0 before 2.4.0p23, 2.3.0 before 2.3.0p43, and end-of-life version 2.2.0, with a CVSS score of 6.3 indicating moderate severity. …

RemediationAI

Within 30 days: Identify affected systems running Checkmk and apply vendor patches as part of regular patch cycle. Monitor vendor channels for patch availability.

Analysis

Detailed AI-generated intelligence summary covering attack vector, impact assessment, affected versions, remediation steps, and indicators of compromise.

POChttps://••••••••••.com/exploit

PATCHhttps://••••••••••.com/patch

ADVISORYhttps://••••••••••.com/advisory

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CVE-2026-2859 vulnerability details – vuln.today

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Checkmk CVE-2026-2859

CVSS VectorNVD

Lifecycle Timeline

DescriptionNVD

AnalysisAI

RemediationAI

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External POC / Exploit Code