CVE-2026-74039 Wazuh 4.0.0 < 4.14.7 API DoS via Deeply Nested JSON auth_context
Authenticated attackers with specific permissions can cause CPU exhaustion and service denial by submitting deeply nested JSON payloads to the Wazuh API.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-74039?
CVE-2026-74039 is a high-severity denial of service vulnerability in Wazuh Wazuh, published on 18 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Wazuh 4.0.0 before 4.14.7 and 5.0.0-beta2 contain a denial of service vulnerability that allows authenticated attackers with allow_run_as enabled to exhaust CPU resources by submitting arbitrarily deeply nested JSON structures to the POST /security/user/authenticate/run_as endpoint. Attackers can repeatedly submit malformed auth_context bodies with unlimited nesting depth to cause the API framework to consume excessive CPU, denying service to all other API consumers.
Which versions are affected by CVE-2026-74039?
It affects 1 product.
Products include Wazuh Wazuh.
How do I fix CVE-2026-74039?
No fix has been published for CVE-2026-74039 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-74039 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-74039 exists.
Other vulnerabilities in Wazuh Wazuh
- CVE-2025-24016 Wazuh Server Deserialization of Untrusted Data
- CVE-2024-32038 Wazuh Analysis Engine Event Decoder Heap-based Buffer Overflow Remote Code Execution Vulnerability
- CVE-2021-44079 Command injection in n/a
- CVE-2024-1243 Remote code execution and local privilege escalation in Wazuh Windows agent via NetNTLMv2 hash theft
- CVE-2026-61800 Wazuh cluster worker file sync allows arbitrary file write under /var/ossec (incomplete fix for CVE-2026-30893)
Sources
Also known as GHSA-5vh8-34r8-q74q.