CVE-2025-64996: Checkmk · Incorrect Permissions
Affects CheckmkSource CVE Database V5
Not known to be exploited · CVSS 4.8 Medium.
Data as of 26 Oct 2026, 10:12 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 1% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:L/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 18 Nov 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Checkmk GmbH Checkmk | Affected
| Fixed in– |
AI-suggested
- Upgrade Checkmk to the latest patched versions: 2.4.0p16 or 2.3.0p41 and above, where this issue is resolved.
- If immediate patching is not possible, manually audit and restrict file permissions for mk_inotify plugin output files to prevent world-readable and writable access. Use chmod to set permissions to owner-only or group-restricted access.
- Limit local user access to monitoring servers strictly to trusted administrators and use hardened user account policies.
- Monitor file system changes and audit logs for unauthorized modifications to monitoring plugin files.
- Employ host-based intrusion detection systems (HIDS) to detect anomalous file permission changes or tampering attempts.
- Review and enforce least privilege principles for all local users on monitoring hosts.
- Regularly verify integrity of monitoring data and cross-check alerts with alternative sources to detect manipulation.
- Incorporate this vulnerability into organizational risk assessments and incident response plans to prepare for potential exploitation scenarios.
Description
In Checkmk versions prior to 2.4.0p16, 2.3.0p41, and all versions of 2.2.0 and older, the mk_inotify plugin creates world-readable and writable files, allowing any local user on the system to read the plugin's output and manipulate it, potentially leading to unauthorized access to or modification of monitoring data.