medium5.9
CVE-2026-21717
A flaw in V8's string hashing mechanism causes integer-like strings to be hashed to their numeric value, making hash collisions trivially predictable.
Impact
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**.
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Nodejs | Node.Js | through 20.20.1 from 22.0.0 through 22.22.1 from 24.0.0 through 24.14.0 from 25.0.0 through 25.8.1 |