CVE-2026-28221: Buffer Overflow in Wazuh 4.8.0-4.14.3

The primary impact of CVE-2026-28221 is a denial-of-service (DoS) condition. An attacker can trigger the buffer overflow by sending specially crafted input to the Wazuh agent, causing the wazuh-remoted process to crash. The vulnerability’s exploitation is dependent on the platform's interpretation of char as a signed type, which can lead to sign-extension issues during formatting. While arbitrary code execution is theoretically possible, it is less likely and would require further exploitation beyond the initial buffer overflow. The blast radius encompasses Wazuh agents and the central Wazuh manager, potentially disrupting threat detection and response capabilities.

1. Veröffentlicht2026-04-29
2. EPSS aktualisiert2026-05-07

The recommended mitigation for CVE-2026-28221 is to upgrade Wazuh to version 4.14.4 or later. If immediate upgrading is not possible, consider implementing network-level filtering to block suspicious traffic targeting the Wazuh agent. While not a complete solution, this can reduce the attack surface. Monitor Wazuh agent logs for unusual crashes or errors that might indicate exploitation attempts. Implement a Web Application Firewall (WAF) or proxy to inspect and filter traffic to the Wazuh agent. After upgrading, confirm the fix by sending a test payload designed to trigger the buffer overflow and verifying that the process does not crash.