CVE-2026-21714
low-risk
Published 2026-03-30
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.
Do I need to act?
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0.02% chance of exploitation
EPSS score — low exploit probability
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Not on CISA KEV list
No confirmed active exploitation reported to CISA
?
Patch status unknown
Check vendor advisories for fix availability and mitigation guidance
5
CVSS 5.3/10
Medium
NETWORK
/ LOW complexity
26
/ 100
low-risk
Severity
21/34 · High
Exploitability
0/34 · Minimal
Exposure
5/34 · Minimal