Wazuh up to 4.14.3 Alert GetAlertData buffer underflow

Summaryinfo

A vulnerability, which was classified as problematic, was found in Wazuh up to 4.14.3. Affected is the function GetAlertData of the component Alert Handler. Such manipulation leads to buffer underflow. This vulnerability is traded as CVE-2026-26204. An attack has to be approached locally. There is no exploit available. You should upgrade the affected component.

Detailsinfo

A vulnerability was found in Wazuh up to 4.14.3 and classified as problematic. Affected by this issue is the function GetAlertData of the component Alert Handler. The manipulation with an unknown input leads to a buffer underflow vulnerability. Using CWE to declare the problem leads to CWE-124. The product writes to a buffer using an index or pointer that references a memory location prior to the beginning of the buffer. Impacted is availability. CVE summarizes:

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.

The advisory is available at github.com. This vulnerability is handled as CVE-2026-26204 since 02/11/2026. The exploitation is known to be easy. Local access is required to approach this attack. Additional levels of successful authentication are needed for exploitation. Technical details are known, but there is no available exploit.

Upgrading to version 4.14.4 eliminates this vulnerability. The upgrade is hosted for download at github.com.

The vulnerability is also documented in the databases at EUVD (EUVD-2026-26259) and CERT Bund (WID-SEC-2026-1295). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Affected

• Open Source Wazuh

Productinfo

Name

• Wazuh

Version

• 4.14.0
• 4.14.1
• 4.14.2
• 4.14.3

Website

• Product: https://github.com/wazuh/wazuh/

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If you want to get best quality of vulnerability data, you may have to visit VulDB.

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