How severe is CVE-2026-21714?

CVE-2026-21714 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability low.

Is CVE-2026-21714 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (36th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-21714?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-21714 have an EU (EUVD) identifier?

Yes. CVE-2026-21714 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-17176.

When was CVE-2026-21714 published?

CVE-2026-21714 was published on 2026-03-30 and last updated on 2026-06-17.

CVE-2026-21714

CVE-2026-21714 is a medium-severity vulnerability with a CVSS 3.x base score of 5.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-401.

Key facts

Severity: Medium (CVSS 3.x base score 5.3)
EPSS exploit prediction: 0% (36th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-17176
Weakness: CWE-401
Published: 2026-03-30
Last modified: 2026-06-17

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.

Frequently asked questions

What is CVE-2026-21714?: 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.
How severe is CVE-2026-21714?: CVE-2026-21714 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability low.
Is CVE-2026-21714 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (36th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-21714?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-21714 have an EU (EUVD) identifier?: Yes. CVE-2026-21714 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-17176.
When was CVE-2026-21714 published?: CVE-2026-21714 was published on 2026-03-30 and last updated on 2026-06-17.

References

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

Other CWE-401 (Missing Release of Memory after Effective Lifetime) vulnerabilities

CVE-2026-46289 — Critical (CVSS 9.8): In the Linux kernel, the following vulnerability has been resolved: lib/scatterlist: fix length calculations in…
CVE-2022-0742 — Critical (CVSS 9.1): Memory leak in icmp6 implementation in Linux Kernel 5.13+ allows a remote attacker to DoS a host by making it go…
CVE-2024-25450 — High (CVSS 8.8): imlib2 v1.9.1 was discovered to mishandle memory allocation in the function init_imlib_fonts().
CVE-2023-33718 — High (CVSS 8.8): mp4v2 v2.1.3 was discovered to contain a memory leak via MP4File::ReadString() at mp4file_io.cpp
CVE-2021-40633 — High (CVSS 8.8): A memory leak (out-of-memory) in gif2rgb in util/gif2rgb.c in giflib 5.1.4 allows remote attackers trigger an out of…
CVE-2021-3492 — High (CVSS 8.8): Shiftfs, an out-of-tree stacking file system included in Ubuntu Linux kernels, did not properly handle faults occurring…

Browse all CWE-401 (Missing Release of Memory after Effective Lifetime) vulnerabilities →