# CVE-2026-111573: Privilege escalation via unprotected Windows agent data folder

Status: published. Published: 2026-11-06. Updated: 2026-11-10.

Incorrect permissions on the Checkmk Windows agent's data directory, caused by a race condition that discards the permission changes during service start, in Checkmk <2.5.0p18, <2.4.0p39, <2.3.0p52 and 2.2.0 (EOL) allow a local user to execute arbitrary code as SYSTEM by placing scripts in the agent's plugins or local folders, and to read the agent controller's private key.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- Checkmk GmbH / Checkmk: ≥ 2.5.0; < 2.5.0p18 (affected, semver); ≥ 2.4.0; < 2.4.0p39 (affected, semver); ≥ 2.3.0; < 2.3.0p52 (affected, semver); 2.2.0 (affected, semver). Source: CNA: Checkmk

## Severity and prioritization

- CVSS 4.0: 6.3 (medium); CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:H/SI:H/SA:H; source: CNA: Checkmk

- CVSS 4.0: 6.3 (medium); CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X; source: NVD: security@checkmk.com

- CISA KEV: No listing in collected sources

- EPSS: 0.13% as of 2026-11-10; percentile 2.71%

- SSVC: exploitation none; automatable no; technical impact partial; source ADP: CISA-ADP

- Weaknesses: CWE-277

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://checkmk.com/werk/19231 (CNA: Checkmk; vendor-advisory)

- https://checkmk.com/werk/19231 (security@checkmk.com)

## Provenance

- CNA: Checkmk: https://www.cve.org/CVERecord?id=CVE-2026-111573; retrieved 2026-11-10; source updated 2026-11-10

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-111573; retrieved 2026-11-06; source updated 2026-11-06

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-111573; retrieved 2026-11-10; source updated Not reported

Revision: 9c89b30975a983ce47b402bef78643c7635789e5675ff6142023569b348f56ed

Canonical: https://y2.dev/cve/CVE-2026-111573

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- OpenAPI: https://y2.dev/api/openapi.yaml. Agent access metadata: https://y2.dev/cve/agent.json.

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