CVE-2026-25224 LOW

CVE-2026-25224: Fastify Vulnerable to DoS via Unbounded Memory Allocation in sendWebStream

Vendor Fastify
Product fastify
Weakness CWE-770 · Uncontrolled resource consumption
Published February 3, 2026
Last update February 4, 2026

CVSS base score

3.7/10
Attack vector Network
Attack complexity High
Privileges required None
User interaction None
Confidentiality None
Integrity None

CVSS vector

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

What the vulnerability does

01Description

Fastify is a fast and low overhead web framework, for Node.js. Prior to version 5.7.3, a denial-of-service vulnerability in Fastify’s Web Streams response handling can allow a remote client to exhaust server memory. Applications that return a ReadableStream (or Response with a Web Stream body) via reply.send() are impacted. A slow or non-reading client can trigger unbounded buffering when backpressure is ignored, leading to process crashes or severe degradation. This issue has been patched in version 5.7.3.

Key dates

02Disclosure timeline

February 3, 2026 CVE published
February 4, 2026 Record updated

Related vulnerabilities

04Related CVE