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.
History

Tue, 03 Feb 2026 21:30:00 +0000

Type Values Removed Values Added
Description 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.
Title Fastify Vulnerable to DoS via Unbounded Memory Allocation in sendWebStream
Weaknesses CWE-770
References
Metrics cvssV3_1

{'score': 3.7, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-02-03T21:21:35.437Z

Reserved: 2026-01-30T14:44:47.327Z

Link: CVE-2026-25224

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-02-03T22:16:31.290

Modified: 2026-02-03T22:16:31.290

Link: CVE-2026-25224

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.