---
id: CVE-2024-7765
aliases:
  - GHSA-6w62-3jvj-mfj6
  - PYSEC-2026-1439
title: H2O Vulnerable to Denial of Service (DoS) via Large GZIP Parsing
summary: H2O Vulnerable to Denial of Service (DoS) via Large GZIP Parsing
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
vendor: h2o
product: h2o
ecosystem: pip
affected:
  - 'h2o >= 3.32.1.2, <= 3.46.0.2'
  - 'ai.h2o:h2o-core >= 3.32.1.2, <= 3.46.0.2'
published: '2025-03-20'
updated: '2026-07-07'
source: OSV
sourceUrl: 'https://osv.dev/vulnerability/GHSA-6w62-3jvj-mfj6'
references:
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2024-7765'
  - url: 'https://github.com/h2oai/h2o-3'
  - url: >-
      https://github.com/h2oai/h2o-3/blob/7d418fa19d3ab434f742818e37f891bef9102c97/h2o-core/src/main/java/water/parser/ParseDataset.java#L900
  - url: 'https://huntr.com/bounties/0e58b1a5-bdca-4e60-af92-09de9c76a9ff'
tags:
  - osv
  - pip
epss: 0.00763
epssPercentile: 0.53429
ingestedAt: '2026-07-08T18:25:46.547Z'
---

## Overview

In h2oai/h2o-3 version 3.46.0.2, a vulnerability exists where uploading and repeatedly parsing a large GZIP file can cause a denial of service. The server becomes unresponsive due to memory exhaustion and a large number of concurrent slow-running jobs. This issue arises from the improper handling of highly compressed data, leading to significant data amplification.

## Affected packages

- `h2o >= 3.32.1.2, <= 3.46.0.2`
- `ai.h2o:h2o-core >= 3.32.1.2, <= 3.46.0.2`

## Remediation

Refer to the advisory for the patched release.