Wazuh is a free and open source platform used for threat prevention, detection, and response. From version 4.8.0 to before version 4.14.4, a stack-based buffer overflow exists in print_hex_string() in wazuh-remoted. The bug is triggered when formatting attacker-controlled bytes using sprintf(dst_buf + 2*i, "%.2x", src_buf[i]) on platforms where char is treated as signed and the compiled code sign-extends bytes before the variadic call. For input bytes such as 0xFF, the formatting can emit "ffffffff" (8 chars) instead of "ff" (2 chars), causing an out-of-bounds write past a fixed 2049-byte stack buffer. The vulnerable path is reachable remotely prior to any agent authentication/registration logic via TCP/1514 when an oversized length prefix causes the “unexpected message (hex)” diagnostic path to run. Additionally, the same unauthenticated oversized-message diagnostic path logs an attacker-controlled hex dump to /var/ossec/logs/ossec.log for each trigger, allowing remote log amplification that can degrade monitoring fidelity and consume disk/I/O. This log amplification is reachable even without triggering the sign-extension overflow (e.g., using bytes < 0x80). This issue has been patched in version 4.14.4.
References
| Link | Resource |
|---|---|
| https://github.com/wazuh/wazuh/releases/tag/v4.14.4 | Release Notes |
| https://github.com/wazuh/wazuh/security/advisories/GHSA-q9vv-7w4c-f4cm | Exploit Vendor Advisory |
| https://github.com/wazuh/wazuh/security/advisories/GHSA-q9vv-7w4c-f4cm | Exploit Vendor Advisory |
Configurations
History
30 Apr 2026, 20:34
| Type | Values Removed | Values Added |
|---|---|---|
| References | () https://github.com/wazuh/wazuh/releases/tag/v4.14.4 - Release Notes | |
| References | () https://github.com/wazuh/wazuh/security/advisories/GHSA-q9vv-7w4c-f4cm - Exploit, Vendor Advisory | |
| CPE | cpe:2.3:a:wazuh:wazuh:*:*:*:*:*:*:*:* | |
| First Time |
Wazuh wazuh
Wazuh |
30 Apr 2026, 15:11
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2026-04-29 19:16
Updated : 2026-04-30 20:34
NVD link : CVE-2026-28221
Mitre link : CVE-2026-28221
CVE.ORG link : CVE-2026-28221
JSON object : View
Products Affected
wazuh
- wazuh
