Disclosure summary
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-reported weakness categories
CWE-328
Source-specific records & product guidance
Sources retain their own attribution and scoring. Follow the original record to confirm affected versions, fixed releases, and configuration conditions.
Microsoft Security Updates (CVRF) · 2026-Mar
Open original source · Updated Sep 27, 2026
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**.
Maximum of vendor-reported product scores; products and fixed builds are associations, not a universal affected-version statement.
Microsoft maximum product score: 5.9
| Vendor | Product / association | Version / bounds |
|---|---|---|
| Microsoft update guide | cbl2 nodejs18 18.20.3-12 on CBL Mariner 2.0 | (MSRC status code 3) |
| Microsoft update guide | azl3 nodejs 20.14.0-14 on Azure Linux 3.0 | (MSRC status code 3) |
| Microsoft update guide | azl3 nodejs24 24.13.0-3 on Azure Linux 3.0 | (MSRC status code 3) |
| Microsoft update guide | cbl2 nodejs18 18.20.3-12 | (MSRC status code 3) |
| Microsoft update guide | cbl2 nodejs18 18.20.3-12 on CBL-Mariner 2.0 | (MSRC status code 3) |
Vendor remediation references
- CBL-Mariner Releases · build 24.14.1-1 · product IDs 21059-17084
- Vendor guidance · product IDs 21059-17084
- Release Notes · product IDs 21130-21692
- Vendor guidance · product IDs 21130-21692
Original records & references
- NIST NVD record
- CVE Program record
- msrc.microsoft.com — Vendor advisory
PUBLISHED 2026-03-31T21:16:14-04:00
MODIFIED 2026-09-27T23:01:47-04:00
INGESTED 2026-10-08T12:45:08-04:00