VULNERABILITY INTELLIGENCE

CVE-2026-21717

CVSS score5.9 MEDIUM
EPSS probability0.27%
CISA KEVNot currently listed
Published2026-03-30
Last modified2026-08-19
CVSS vectorCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

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**.

Weakness classification

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

Primary references