Fastify Vulnerable to DoS via Unbounded Memory Allocation in sendWebStream
GHSA-mrq3-vjjr-p77c · CVE-2026-25224
Published · Modified
AI SAST
Find this class of vulnerability in your own code
Corgea's AI-native static analysis detects vulnerabilities like this one across your repositories, ranks them by exploitability, and returns review-ready fixes.
Description
Impact
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.
Patches
The issue is fixed in Fastify 5.7.3. Users should upgrade to 5.7.3 or later.
Workarounds
Avoid sending Web Streams from Fastify responses (e.g., ReadableStream or Response bodies). Use Node.js streams (stream.Readable) or buffered payloads instead until the project can upgrade.
References
References
- WEB https://github.com/fastify/fastify/security/advisories/GHSA-mrq3-vjjr-p77c
- ADVISORY https://nvd.nist.gov/vuln/detail/CVE-2026-25224
- WEB https://github.com/fastify/fastify/commit/eb11156396f6a5fedaceed0140aed2b7f026be37
- WEB https://hackerone.com/reports/3524779
- PACKAGE https://github.com/fastify/fastify
Ready to move
Start Securing
Free, no credit card | First findings in minutes