# CVE-2026-74040: Wazuh arbitrary file overwrite in cluster worker communication

Source: https://junglewise.ai/threats/cve-2026-74040-wazuh-versions-from-3-9-0-before-4-14-8-contain-an-arbitrary-file  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-13. Updated: 2026-10-16  
License: CC BY 4.0 with a link back

CVE-2026-74040 · Severity: critical · CVSS 9.1 · Published 2026-10-13

Wazuh is a security monitoring platform used to protect corporate networks by monitoring endpoints and collecting security logs. A vulnerability in how the manager processes file updates from cluster workers allows an attacker controlling a compromised worker to overwrite critical configuration files on the manager, leading to complete remote code execution with root privileges across the manager and every connected agent.

Technologies: [Wazuh Manager](https://junglewise.ai/threats/technologies/wazuh-manager). Vendors: [Wazuh](https://junglewise.ai/threats/vendors/wazuh).

## Quick answers

**Is CVE-2026-74040 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-74040 being exploited in the wild.

**How severe is CVE-2026-74040?** Critical severity, with a CVSS score of 9.1, published 13 October 2026.

**Which products and versions are affected?** Wazuh Manager 3.9.0 before 4.14.8.

**Is there a fix for CVE-2026-74040?** Yes: fixed in 4.14.8. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-74040 attacked?** It is attacked over the network, in a hosted service.

**Am I affected by CVE-2026-74040?** Check whether you run Wazuh Manager at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in 4.14.8

## Technical details

The MasterHandler.process_files_from_worker function in the cluster communication layer contains two independent defects: a basename bypass of the excluded_files blocklist using trailing slashes (os.path.basename("etc/ossec.conf/") == ""), and missing direction validation allowing workers to send master-sourced files without authorization. An attacker with cluster key access can inject malicious XML into ossec.conf or agent.conf to achieve root RCE via the wodle command execution mechanism.

## Affected products

- Wazuh Manager 3.9.0 before 4.14.8

## Timeline

- 2026-10-13: disclosed
- 2026-09-25: patched

## References

- [https://github.com/wazuh/wazuh/releases/tag/v4.14.8](https://github.com/wazuh/wazuh/releases/tag/v4.14.8)
- [https://github.com/wazuh/wazuh/security/advisories/GHSA-88p6-7cm8-xwj8](https://github.com/wazuh/wazuh/security/advisories/GHSA-88p6-7cm8-xwj8)

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