CVE-2026-56699 -- CVSS 10.0 Vulnerability Briefing

CVE-2026-56699 | CVSS 10.0 (Critical) | Exploit: No known exploit

What Is It

CVE-2026-56699 is an NDJSON injection vulnerability in Wazuh Manager before version 5.0.0-beta3, where insufficient input sanitization in the OpenSearch bulk request construction path allows enrolled agents to inject arbitrary data operations.

Technical Detail

The flaw exists in Wazuh Manager's handling of the DataValue.index field, which is passed unsanitized into OpenSearch bulk API requests formatted as NDJSON. An attacker controlling an enrolled agent can craft a malicious index value containing newline characters and valid NDJSON syntax, causing the server to interpret injected content as legitimate bulk operations. Depending on the OpenSearch cluster's permissions and configuration, this could allow unauthorized data manipulation, deletion of indices, or exfiltration of stored security event data, with a CVSS score of 10.0 indicating the highest possible severity assessment.

Exploitation Status

No known exploit code has been identified at this time, and this CVE is not listed in the CISA Known Exploited Vulnerabilities catalog. The exploit maturity is currently assessed as no known exploit, meaning no public proof-of-concept or operational tooling has been confirmed as of July 22, 2026. However, the injection primitive is conceptually straightforward and the attack surface is accessible to any enrolled agent, which lowers the practical barrier for exploitation once the vulnerability is more widely understood.

Who Is Targeting This

No specific threat actor attribution at this time. Neither confirmed nor reported threat actor involvement has been identified in connection with this vulnerability.

What To Do

Upgrade Wazuh Manager to version 5.0.0-beta3 or later, which addresses the missing escaping of the DataValue.index field. Organizations unable to patch immediately should restrict agent enrollment to trusted, authenticated endpoints and apply network-level controls to limit which systems can communicate with the Wazuh Manager's ingestion pipeline. Monitor OpenSearch audit logs for anomalous bulk API operations, particularly those containing unexpected index names, delete actions, or operations originating from agent-facing components. Given that enrolled agents are the attack vector, reviewing and tightening agent authentication and authorization policies is a practical interim control.