---
id: CVE-2024-6863
aliases:
  - GHSA-m37h-8r48-2cxj
  - PYSEC-2026-1442
title: H2O Vulnerable to Execution of Arbitrary Files
summary: H2O Vulnerable to Execution of Arbitrary Files
severity: medium
cvss: 6.5
cvssVector: 'CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L'
vendor: h2o
product: h2o
ecosystem: pip
affected:
  - 'h2o >= 3.32.1.2, <= 3.46.0'
  - 'ai.h2o:h2o-core >= 3.32.1.2, <= 3.46.0'
published: '2025-03-20'
updated: '2026-07-07'
source: OSV
sourceUrl: 'https://osv.dev/vulnerability/GHSA-m37h-8r48-2cxj'
references:
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2024-6863'
  - url: 'https://github.com/h2oai/h2o-3'
  - url: >-
      https://github.com/h2oai/h2o-3/blob/a20b5b19b769866ee24b217ee78b820e64c1cd6a/h2o-core/src/main/java/water/tools/EncryptionTool.java#L49
  - url: 'https://huntr.com/bounties/10f55937-0cba-4530-897f-2abf30ed5270'
tags:
  - osv
  - pip
epss: 0.0035
epssPercentile: 0.28708
ingestedAt: '2026-07-08T18:25:50.928Z'
---

## Overview

In h2oai/h2o-3 version 3.46.0, an endpoint exposing a custom EncryptionTool allows an attacker to encrypt any files on the target server with a key of their choosing. The chosen key can also be overwritten, resulting in ransomware-like behavior. This vulnerability makes it possible for an attacker to encrypt arbitrary files with keys of their choice, making it exceedingly difficult for the target to recover the keys needed for decryption.

## Affected packages

- `h2o >= 3.32.1.2, <= 3.46.0`
- `ai.h2o:h2o-core >= 3.32.1.2, <= 3.46.0`

## Remediation

Refer to the advisory for the patched release.