CVE-2026-21717
Published: March 26, 2026Last modified: March 28, 2026
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**.
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 5.9 |
| Attack Vector | NETWORK |
| Attack complexity | HIGH |
| Privileges required | NONE |
| User interaction | NONE |
| Scope | UNCHANGED |
| Confidentiality | NONE |
| Integrity impact | NONE |
| Availability impact | HIGH |
| Vector | CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H |
Status
| Product | Release | Package | Status |
|---|---|---|---|
| Alpaquita Linux | 23 LTS | nodejs | Fixed (20.20.2-r0) |
| 25 LTS | nodejs | Fixed (22.22.2-r0) | |
| Stream | nodejs | Fixed (24.14.1-r0) | |
| Hardened Containers | 23 LTS | nodejs | Fixed (20.20.2-r0) |
| 25 LTS | nodejs | Fixed (22.22.2-r0) | |
| Stream | nodejs | Fixed (24.14.1-r0) |