---
id: CVE-2026-21714
title: >-
  A memory leak occurs in Node.js HTTP/2 servers when a client sends
  WINDOW_UPDATE frames on stream 0 (connection-level) that cause the flow
  control window to exceed the maximum value of 2³¹-1
summary: >-
  A memory leak occurs in Node.js HTTP/2 servers when a client sends
  WINDOW_UPDATE frames on stream 0 (connection-level) that cause the flow
  control window to exceed the maximum value of 2³¹-1. The server correctly
  sends a GOAWAY frame, bu…
severity: medium
cvss: 5.3
cvssVector: 'CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L'
cwe:
  - CWE-401
vendor: nodejs
product: node.js
affected:
  - node.js <= 20.20.1
  - 'node.js >= 22.0.0, <= 22.22.1'
  - 'node.js >= 24.0.0, <= 24.14.0'
  - 'node.js >= 25.0.0, <= 25.8.1'
published: '2026-03-30'
updated: '2026-08-19'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-21714'
references:
  - url: 'https://nodejs.org/en/blog/vulnerability/march-2026-security-releases'
    label: support@hackerone.com
tags:
  - nvd
epss: 0.00454
epssPercentile: 0.36666
ingestedAt: '2026-08-19T13:39:32.812Z'
---

## Overview

A memory leak occurs in Node.js HTTP/2 servers when a client sends WINDOW_UPDATE frames on stream 0 (connection-level) that cause the flow control window to exceed the maximum value of 2³¹-1. The server correctly sends a GOAWAY frame, but the Http2Session object is never cleaned up.

This vulnerability affects HTTP2 users on Node.js 20, 22, 24 and 25.

## Affected

- `node.js <= 20.20.1`
- `node.js >= 22.0.0, <= 22.22.1`
- `node.js >= 24.0.0, <= 24.14.0`
- `node.js >= 25.0.0, <= 25.8.1`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.