What is CVE-2026-21712?

CVE-2026-21712 is a medium-severity vulnerability in Node.js Node, classified under Improper Input Validation. CVSS score: 6.5/10. Published 2026-03-30.

How severe is CVE-2026-21712?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Improper input validation in Node.js Node

CVE-2026-21712

A flaw in Node.js URL processing causes an assertion failure in native code when `url.format()` is called with a malformed internationalized domain name (IDN) containing invalid characters, crashing the Node.js process.

Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)

Published 2026-03-30 · last modified 2026-08-19.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.003 (22.4th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 22nd percentile — 22.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000

Affected products

Node.js Node — versions 24.14.0, 25.8.1
Node.js

Weakness classification (CWE)

CWE-20 — Improper Input Validation

References

nodejs.org/en/blog/vulnerability/march-2026-security-releases (Vendor Advisory)
hackerone.com/reports/3546390 (Third Party Advisory, Issue Tracking)

Frequently asked questions

What is CVE-2026-21712?: CVE-2026-21712 is a medium-severity vulnerability in Node.js Node, classified under Improper Input Validation. CVSS score: 6.5/10. Published 2026-03-30.
How severe is CVE-2026-21712?: Medium severity. CVSS v3 base score is 6.5 out of 10.