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.
History

Wed, 01 Apr 2026 02:15:00 +0000

Type Values Removed Values Added
Title Node.js HTTP/2 Server Memory Leak due to WINDOW_UPDATE Frames Node.js: Node.js: Memory leak and Denial of Service via crafted HTTP/2 WINDOW_UPDATE frames
First Time appeared Nodejs
Nodejs nodejs
Weaknesses CWE-400 CWE-772
Vendors & Products Nodejs
Nodejs nodejs
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L'}

threat_severity

Moderate


Tue, 31 Mar 2026 18:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-401
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Tue, 31 Mar 2026 03:00:00 +0000

Type Values Removed Values Added
Title Node.js HTTP/2 Server Memory Leak due to WINDOW_UPDATE Frames
Weaknesses CWE-400

Mon, 30 Mar 2026 19:30:00 +0000

Type Values Removed Values Added
Description 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.
References
Metrics cvssV3_0

{'score': 5.3, 'vector': 'CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L'}


cve-icon MITRE

Status: PUBLISHED

Assigner: hackerone

Published:

Updated: 2026-03-31T18:05:22.283Z

Reserved: 2026-01-04T15:00:06.574Z

Link: CVE-2026-21714

cve-icon Vulnrichment

Updated: 2026-03-31T16:15:18.022Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-03-30T20:16:19.573

Modified: 2026-04-01T14:24:21.833

Link: CVE-2026-21714

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-03-30T19:07:28Z

Links: CVE-2026-21714 - Bugzilla