CVE-2026-40879 HIGH

CVE-2026-40879: Nest: DoS via Recursive handleData in JsonSocket (TCP Transport)

Vendor Nestjs
Product nest
Weakness CWE-674
Published April 21, 2026
Last update April 21, 2026

CVSS base score

7.5/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality None
Integrity None

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

April 21, 2026 CVE published
April 21, 2026 Record updated