CVE-2021-26814 Improper Input Validation (RCE)

What is CVE-2021-26814?

CVE-2021-26814 is a high-severity code injection vulnerability in Wazuh Wazuh, published on 6 Mar 2021. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

Wazuh API in Wazuh from 4.0.0 to 4.0.3 allows authenticated users to execute arbitrary code with administrative privileges via /manager/files URI. An authenticated user to the service may exploit incomplete input validation on the /manager/files API to inject arbitrary code within the API service script.

Weakness: CWE-22

Which versions are affected by CVE-2021-26814?

2 open source packages ship an affected version, including wazuh. It affects 1 product.

Products include Wazuh Wazuh.

How do I fix CVE-2021-26814?

Upgrade wazuh to 4.0.4 or later.

Upgrade, and never evaluate templates, expressions or code built from user input. More about Code injection.

Is CVE-2021-26814 being exploited?

There is no known exploitation of CVE-2021-26814 in the wild and no public exploit code.

Public exploit code: 3 proofs of concept on GitHub.

Other vulnerabilities in Wazuh Wazuh

• CVE-2025-24016 Wazuh Server Deserialization of Untrusted Data Exploited Critical 9.9
• CVE-2024-32038 Wazuh Analysis Engine Event Decoder Heap-based Buffer Overflow Remote Code Execution Vulnerability Critical 9.8
• CVE-2021-44079 Command injection in n/a Critical 9.8
• CVE-2024-1243 Remote code execution and local privilege escalation in Wazuh Windows agent via NetNTLMv2 hash theft Critical 9.5
• CVE-2026-61800 Wazuh cluster worker file sync allows arbitrary file write under /var/ossec (incomplete fix for CVE-2026-30893) Critical 9.1

All Wazuh Wazuh vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-w36g-q975-37rg.