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, 10 Feb 2026 19:30:00 +0000

Type Values Removed Values Added
CPEs cpe:2.3:a:fastify:fastify:*:*:*:*:*:node.js:*:*

Wed, 04 Feb 2026 17:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Wed, 04 Feb 2026 12:15:00 +0000

Type Values Removed Values Added
First Time appeared Fastify
Fastify fastify
Vendors & Products Fastify
Fastify fastify
References
Metrics threat_severity

None

threat_severity

Low


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

Updated: 2026-02-04T16:20:32.845Z

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

Link: CVE-2026-25224

cve-icon Vulnrichment

Updated: 2026-02-04T16:20:29.894Z

cve-icon NVD

Status : Analyzed

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

Modified: 2026-02-10T19:24:48.703

Link: CVE-2026-25224

cve-icon Redhat

Severity : Low

Publid Date: 2026-02-03T21:21:35Z

Links: CVE-2026-25224 - Bugzilla