# 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.

- **Severity:** High 7.1 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 18 Aug 2026
- **Updated:** 1 Oct 2026
- **Also known as:** GHSA-5vh8-34r8-q74q

## 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.

Weakness: CWE-770 (Allocation of Resources Without Limits or Throttling), CWE-1333 (Inefficient Regular Expression Complexity)

## Which versions are affected by CVE-2026-74039?

It affects 1 product.


Products: 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.

## 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](https://insights.sbomify.com/CVE-2025-24016/): Wazuh Server Deserialization of Untrusted Data (critical 9.9, exploited in the wild)
- [CVE-2024-32038](https://insights.sbomify.com/CVE-2024-32038/): Wazuh Analysis Engine Event Decoder Heap-based Buffer Overflow Remote Code Execution Vulnerability (critical 9.8)
- [CVE-2021-44079](https://insights.sbomify.com/CVE-2021-44079/): Command injection in n/a (critical 9.8)
- [CVE-2024-1243](https://insights.sbomify.com/CVE-2024-1243/): Remote code execution and local privilege escalation in Wazuh Windows agent via NetNTLMv2 hash theft (critical 9.5)
- [CVE-2026-61800](https://insights.sbomify.com/CVE-2026-61800/): Wazuh cluster worker file sync allows arbitrary file write under /var/ossec (incomplete fix for CVE-2026-30893) (critical 9.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-74039 and fix it if it is affected.

What it is: 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.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-74039 exists.

Affected product: Wazuh Wazuh. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-74039/ (Markdown: https://insights.sbomify.com/CVE-2026-74039/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-74039
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-74039
- OSV: https://osv.dev/vulnerability/CVE-2026-74039

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-74039/
Summaries are generated and may contain mistakes; the official description above is the record.