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.
Advisories
Source ID Title
Github GHSA Github GHSA GHSA-mrq3-vjjr-p77c Fastify Vulnerable to DoS via Unbounded Memory Allocation in sendWebStream
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

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'}


Projects

Sign in to view the affected projects.

cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

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 : Awaiting Analysis

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

Modified: 2026-02-04T16:33:44.537

Link: CVE-2026-25224

cve-icon Redhat

Severity : Low

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

Links: CVE-2026-25224 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-02-04T12:05:59Z

Weaknesses