How severe is CVE-2025-39666?

CVE-2025-39666 has a CVSS 3.x base score of 7.3, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2025-39666 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (2nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2025-39666?

CVE-2025-39666 primarily affects Checkmk. In total, 142 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2025-39666?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2025-39666 have an EU (EUVD) identifier?

Yes. CVE-2025-39666 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-209262.

When was CVE-2025-39666 published?

CVE-2025-39666 was published on 2026-04-07 and last updated on 2026-06-17.

CVE-2025-39666

CVE-2025-39666 is a high-severity vulnerability in Checkmk with a CVSS 3.x base score of 7.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-426.

Key facts

Severity: High (CVSS 3.x base score 7.3)
CVSS v4: 9.3
EPSS exploit prediction: 0% (2nd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-209262
Weakness: CWE-426
Affected product: Checkmk
Published: 2026-04-07
Last modified: 2026-06-17

Description

Local privilege escalation in Checkmk 2.2.0 (EOL), Checkmk 2.3.0 before 2.3.0p46, Checkmk 2.4.0 before 2.4.0p25, and Checkmk 2.5.0 (beta) before 2.5.0b3 allows a site user to escalate their privileges to root, by manipulating files in the site context that are processed when the `omd` administrative command is run by root.

Frequently asked questions

What is CVE-2025-39666?: Local privilege escalation in Checkmk 2.2.0 (EOL), Checkmk 2.3.0 before 2.3.0p46, Checkmk 2.4.0 before 2.4.0p25, and Checkmk 2.5.0 (beta) before 2.5.0b3 allows a site user to escalate their privileges to root, by manipulating files in the site context that are processed when the `omd` administrative command is run by root.
How severe is CVE-2025-39666?: CVE-2025-39666 has a CVSS 3.x base score of 7.3, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2025-39666 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (2nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-39666?: CVE-2025-39666 primarily affects Checkmk. In total, 142 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2025-39666?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2025-39666 have an EU (EUVD) identifier?: Yes. CVE-2025-39666 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-209262.
When was CVE-2025-39666 published?: CVE-2025-39666 was published on 2026-04-07 and last updated on 2026-06-17.

References

https://checkmk.com/werk/18891

Affected products (142)

cpe:2.3:a:checkmk:checkmk:2.2.0:-:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:b1:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:b2:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:b3:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:b4:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:b5:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:b6:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:b7:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:b8:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:i1:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:p1:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:p10:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:p11:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:p12:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:p13:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:p14:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:p15:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:p16:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:p17:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:p18:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:p19:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:p2:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:p20:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:p21:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:p22:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:p23:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:p24:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:p25:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:p26:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:p27:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:p28:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:p29:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:p3:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:p30:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:p31:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:p32:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:p33:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:p34:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:p35:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.2.0:p36:*:*:*:*:*:*

More vulnerabilities in Checkmk

CVE-2022-46836 — Critical (CVSS 9.1): PHP code injection in watolib auth.php and hosttags.php in Tribe29's Checkmk <= 2.1.0p10, Checkmk <= 2.0.0p27, and…
CVE-2026-24096 — High (CVSS 8.8): Insufficient permission validation on multiple REST API Quick Setup endpoints in Checkmk 2.5.0 (beta) before version…
CVE-2025-32918 — High (CVSS 8.8): Improper neutralization of Livestatus command delimiters in autocomplete endpoint within the RestAPI of Checkmk…
CVE-2025-1712 — High (CVSS 8.8): Argument injection in special agent configuration in Checkmk <2.4.0p1, <2.3.0p32, <2.2.0p42 and 2.1.0 allows…
CVE-2025-32917 — High (CVSS 8.8): Privilege escalation in jar_signature agent plugin in Checkmk versions <2.4.0b7 (beta), <2.3.0p32, <2.2.0p42, and…
CVE-2024-38865 — High (CVSS 8.8): Improper neutralization of livestatus command delimiters in a specific endpoint within RestAPI of Checkmk prior to…

All CVEs affecting Checkmk →

Other CWE-426 (Untrusted Search Path) vulnerabilities

CVE-2026-45772 — Critical (CVSS 9.8): Turborepo is a high-performance build system for JavaScript and TypeScript codebases. From 1.1.0 to before 2.9.14,…
CVE-2025-26155 — Critical (CVSS 9.8): NCP Secure Enterprise Client 13.18 and NCP Secure Entry Windows Client 13.19 have an Untrusted Search Path…
CVE-2024-53866 — Critical (CVSS 9.8): The package manager pnpm prior to version 9.15.0 seems to mishandle overrides and global cache: Overrides from one…
CVE-2024-38462 — Critical (CVSS 9.8): iRODS before 4.3.2 provides an msiSendMail function with a problematic dependency on the mail binary, such as in the…
CVE-2023-30330 — Critical (CVSS 9.8): SoftExpert (SE) Excellence Suite 2.x versions before 2.1.3 is vulnerable to Local File Inclusion in the function…
CVE-2022-24826 — Critical (CVSS 9.8): On Windows, if Git LFS operates on a malicious repository with a `..exe` file as well as a file named `git.exe`, and…

Browse all CWE-426 (Untrusted Search Path) vulnerabilities →