---
id: "CVE-2024-5986"
kind: "vulnerability"
aliases: ["CVE-2024-5986", "GHSA-wj3h-wx8g-x699"]
title: "H2O has an External Control of File Name or Path vulnerability"
severity: "critical"
cvss: 9.1
epss: 0.00714
exploited: false
status: "open"
category: "ai-tooling"
products: [{"name": "ai.h2o:h2o-core", "fixed": [], "affected": "<= 3.46.0.1", "ecosystem": "maven"}, {"name": "h2o", "fixed": [], "affected": "<= 3.46.0.1", "ecosystem": "pypi"}]
ecosystems: ["maven", "pypi"]
tags: ["ai-tooling", "cwe-73", "h2o", "java", "machine-learning", "python", "self-hosted"]
not_affected_if: ["local-only-use", "network-isolated"]
published_at: "2026-02-02T11:16:16+00:00"
first_seen_at: "2026-10-27T16:35:55+00:00"
updated_at: "2026-10-27T17:03:04+00:00"
sources: [{"source": "ghsa", "url": "https://github.com/advisories/GHSA-wj3h-wx8g-x699", "first_seen_at": "2026-10-27T16:35:55+00:00"}, {"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2024-5986", "first_seen_at": "2026-10-27T17:03:04+00:00"}]
---

# H2O has an External Control of File Name or Path vulnerability

H2O-3 machine learning server lets remote users write arbitrary data to any file on the host through the /3/Parse and /3/Frames export endpoints. An attacker can overwrite files such as SSH keys or scripts, which can lead to remote code execution and full system takeover.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- maven:ai.h2o:h2o-core affected <= 3.46.0.1 fixed ?
- pypi:h2o affected <= 3.46.0.1 fixed ?

## How to check

- Check the installed h2o version with `pip show h2o` or the Maven `ai.h2o:h2o-core` version; affected versions are `3.46.0.1` and below.
- Check whether the H2O server is reachable from untrusted networks and whether `/3/Parse` and `/3/Frames` are exposed.

## Fix

- Upgrade the `h2o` PyPI package and `ai.h2o:h2o-core` Maven artifact to a fixed release; the fixed version is unknown from the sources.
- Until patched, restrict network access to the H2O server so it is not reachable from untrusted clients.

## Timeline

- 2026-10-27T16:35:55+00:00 ghsa https://github.com/advisories/GHSA-wj3h-wx8g-x699
- 2026-10-27T17:03:04+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2024-5986

## From the sources

A vulnerability in h2oai/h2o-3 version 3.46.0.1 allows remote attackers to write arbitrary data to any file on the server. This is achieved by exploiting the `/3/Parse` endpoint to inject attacker-controlled data as the header of an empty file, which is then exported using the `/3/Frames/framename/export` endpoint. The impact of this vulnerability includes the potential for remote code execution and complete access to the system running h2o-3, as attackers can overwrite critical files such as private SSH keys or script files.

---

_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_