CVE-2026-40106Public exploit

Agent crash via unchecked registry path concatenation

Published Jul 16, 2026 · Updated Jul 17, 2026

Heap-based buffer overflow in Wazuh agent 4.6.0 through 4.14.4 allows local users to crash syscheck through a crafted registry key. The w_expand_by_wildcard function in syscheck_op.c copies the base path, matched subkey, and remainder with strcpy and strcat into a fixed 256-byte heap buffer without checking their combined length. Exploitation requires a wildcard-monitored registry path writable by a low-privileged Windows user; repeated agent crashes are demonstrated, while SYSTEM-level execution is theoretical.

CVSS severity4.7
Medium
EPSS probability0.13%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Heap-based buffer overflow in Wazuh agent 4.6.0 through 4.14.4 allows local users to crash syscheck through a crafted registry key. The w_expand_by_wildcard function in syscheck_op.c copies the base path, matched subkey, and remainder with strcpy and strcat into a fixed 256-byte heap buffer without checking their combined length. Exploitation requires a wildcard-monitored registry path writable by a low-privileged Windows user; repeated agent crashes are demonstrated, while SYSTEM-level execution is theoretical.

The record

CVE
CVE-2026-40106
Published
Jul 16, 2026
Updated
Jul 17, 2026
Vendor
Wazuh
Product
Wazuh
Classifications
CWE-122, T1562.001
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 16, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 17, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=>= 4.6.0, < 4.14.5

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Wazuh · Wazuhversion=>= 4.6.0, < 4.14.5

Published CVSS scores

4.7GitHub, Inc.CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-122Heap-based Buffer Overflow
T1562.001Impair Defenses: Disable or Modify Tools

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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