CVE-2026-21717

Published Mar 30, 2026

Last updated 18 days ago

Overview

Description
A flaw in V8's string hashing mechanism causes integer-like strings to be hashed to their numeric value, making hash collisions trivially predictable. By crafting a request that causes many such collisions in V8's internal string table, an attacker can significantly degrade performance of the Node.js process. The most common trigger is any endpoint that calls `JSON.parse()` on attacker-controlled input, as JSON parsing automatically internalizes short strings into the affected hash table. This vulnerability affects **20.x, 22.x, 24.x, and 25.x**.
Source
support@hackerone.com
NVD status
Analyzed
Products
node.js

Risk scores

CVSS 3.1

Type
Primary
Base score
5.9
Impact score
3.6
Exploitability score
2.2
Vector string
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Severity
MEDIUM

CVSS 3.0

Type
Secondary
Base score
5.9
Impact score
3.6
Exploitability score
2.2
Vector string
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Severity
MEDIUM

Weaknesses

134c704f-9b21-4f2e-91b3-4a467353bcc0
CWE-328

Social media

Hype score
Not currently trending

Configurations

References

Sources include official advisories and independent security research.