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**.

• cbl2 nodejs18 18.20.3-12 on CBL Mariner 2.0
• azl3 nodejs 20.14.0-14 on Azure Linux 3.0
• azl3 nodejs24 24.13.0-3 on Azure Linux 3.0
• cbl2 nodejs18 18.20.3-12
• cbl2 nodejs18 18.20.3-12 on CBL-Mariner 2.0

CBL-Mariner Releases Release Notes

1. Apr 1, 2026 at 1:16 AM UTC
   Published by Microsoft Security Response Center

   The publication date reported by the vendor.

2. Sep 28, 2026 at 3:01 AM UTC
   Updated by Microsoft Security Response Center

   The vendor changed the advisory after it was first published.

3. Oct 2, 2026 at 12:40 PM UTC
   Added to SecurityAlert

   We collected the advisory from the official source.

4. Oct 3, 2026 at 1:00 PM UTC
   Confirmed at the source

   Our collector saw this advisory during a later source check.