CVE-2025-39664Public exploitNetwork attack vector

Authenticated site disruption via post-validation macro expansion

Published Oct 9, 2025 · Updated Oct 9, 2025

Checkmk 2.1.0 and affected 2.2.0, 2.3.0, and 2.4.0 report schedulers allow remote authenticated users to disrupt sites via path traversal. Filename and subdirectory checks run before macro expansion, so traversal sequences in $TITLE$ place generated .mk and .pdf pairs outside the archive; affected branches end before 2.2.0p46, 2.3.0p38, and 2.4.0p13. The default Manage Own Scheduled Reports permission is sufficient, and overwriting .mk configuration files interrupts the affected site.

CVSS severity7.1
High
EPSS probability0.69%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Checkmk 2.1.0 and affected 2.2.0, 2.3.0, and 2.4.0 report schedulers allow remote authenticated users to disrupt sites via path traversal. Filename and subdirectory checks run before macro expansion, so traversal sequences in $TITLE$ place generated .mk and .pdf pairs outside the archive; affected branches end before 2.2.0p46, 2.3.0p38, and 2.4.0p13. The default Manage Own Scheduled Reports permission is sufficient, and overwriting .mk configuration files interrupts the affected site.

The record

CVE
CVE-2025-39664
Published
Oct 9, 2025
Updated
Oct 9, 2025
Vendor
Checkmk GmbH
Product
Checkmk
Classifications
CWE-22, T1499.004
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 9, 2025CVE publishedPublication date reported by the CVE source.
  2. Oct 9, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=2.1.0
  2. Affected versionversion=2.2.0 <2.2.0p46
  3. Affected versionversion=2.3.0 <2.3.0p38
  4. Affected versionversion=2.4.0 <2.4.0p13

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Checkmk GmbH · Checkmkversion=2.1.0; version=2.2.0 <2.2.0p46; version=2.3.0 <2.3.0p38; version=2.4.0 <2.4.0p13

Published CVSS scores

7.1SBA ResearchCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H
6.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
7.1Checkmk GmbHCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
T1499.004Application or System Exploitation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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