CVE-2026-21714 PUBLISHED

Assigner: hackerone
Reserved: 04.01.2026 Published: 30.03.2026 Updated: 30.03.2026

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.

Metrics

CVSS 3.0

CVSS Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
CVSS Score: 5.3

Attack Vector	Network	Scope	Unchanged
Attack Complexity	Low	Confidentiality Impact	None
Privileges Required	None	Integrity Impact	None
User Interaction	None	Availability Impact	Low

CVSS 3.0

Product Status

Vendor	nodejs
Product	node
Versions	Default: unaffected affected from 20.20.1 to 20.20.1 (incl.) affected from 22.22.1 to 22.22.1 (incl.) affected from 24.14.0 to 24.14.0 (incl.) affected from 25.8.1 to 25.8.1 (incl.)

References

https://nodejs.org/en/blog/vulnerability/march-2026-security-releases