CVE-2026-40879: Nestjs Nest

High severity, CVSS 7.5. EPSS: 0.5% chance of exploitation in the next 30 days.

Nest is a framework for building scalable Node.js server-side applications. Prior to 11.1.19, when an attacker sends many small, valid JSON messages in one TCP frame, handleData() recurses once per message; the buffer shrinks each call. maxBufferSize is never reached; call stack overflows instead. A ~47 KB payload is sufficient to trigger RangeError. This vulnerability is fixed in 11.1.19.

Affected products

• Nestjs Nest: before 11.1.19 (fixed in 11.1.19)

Published 2026-04-21. Last modified 2026-06-17.