CVE-2026-26204 MEDIUM

CVE-2026-26204: Wazuh: Heap-based NULL WRITE Buffer Underflow in GetAlertData

Vendor Wazuh
Product wazuh
Weakness CWE-124
Published April 29, 2026
Last update April 30, 2026

CVSS base score

4.4/10
Attack vector Local
Attack complexity Low
Privileges required High
User interaction None
Confidentiality None
Integrity None

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H

What the vulnerability does

01Description

Wazuh is a free and open source platform used for threat prevention, detection, and response. From version 1.0.0 to before version 4.14.4, a heap-based out-of-bounds WRITE occurs in GetAlertData, resulting in writing a NULL byte exactly 1 byte before the start of the buffer allocated by strdup. Due to unsigned integer underflow and pointer arithmetic wrapping, the write lands at offset -1 from the buffer, corrupting heap metadata. A malicious actor can potentially leverage this issue through a compromised agent to cause denial of service or heap corruption by injecting a specially crafted alert into the alerts log file monitored by wazuh-logcollector. This issue has been patched in version 4.14.4.

Key dates

02Disclosure timeline

April 29, 2026 CVE published
April 30, 2026 Record updated