Vulnerability · Published Apr 29, 2026 · Assigned by GitHub_M
CVE-2026-26204Wazuh: Heap-based NULL WRITE Buffer Underflow in GetAlertData
Medium 4.4
In plain English
A medium-severity security flaw in wazuh from wazuh. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 6% of all known vulnerabilities).
Official description
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.
Affected products (as reported)
Weakness: CWE-124, CWE-191 · Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
References
- https://github.com/wazuh/wazuh/security/advisories/GHSA-j4c7-hwjw-8857 x_refsource_CONFIRM
- https://github.com/wazuh/wazuh/releases/tag/v4.14.4 x_refsource_MISC