Fastify
CVE-2026-25224
LOW
GHSA-mrq3-vjjr-p77c
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A06:2021 - Vulnerable and Outdated Components
ASVS 5.0
V14 - Configuration Dependency management, component inventory
MITRE ATT&CK
1 technique across 1 tactic: Impact The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Impact | CVSS 3.7 (LOW). Attack vector: Network. Complexity: High. Privileges required: None. User interaction: None. Exploitable via remote/network. |
| Exploit ScenarioDerived | A remote attacker could exploit this vulnerability to a remote client to exhaust server memory. |
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Alert meAnalysisAIv1 – Mar 12, 2026
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...
Earlier versions of this analysis (1)
Fastify versions up to 5.7.3 is affected by allocation of resources without limits or throttling (CVSS 3.7).
RemediationAI
A vendor patch is available — apply it immediately. Fixed in version 5.7.3.. Restrict network access to the affected service where possible.
Affected Packages
Source: OSV (Open Source Vulnerabilities)
Affects your stack
Affects 1 package in npm
Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
This vulnerability (CWE-770: Allocation of Resources Without Limits or Throttling) affects Fastify. 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 ve
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- Exploit and PoC references, threat intelligence from 22 sources
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Severity by source
AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L
Primary rating from GitHub Advisory · only source for this CVE.
CVSS VectorGitHub Advisory
Lifecycle Timeline
2DescriptionGitHub Advisory
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.
Blast Radius
ecosystem impact- 24 npm packages depend on fastify (11 direct, 13 indirect)
Ecosystem-wide dependent count for version 5.7.3.
Executive ViewAI
CVE-2026-25224 is a low-severity vulnerability in Fastify (CVSS 3.7). The limited severity suggests constrained impact, typically requiring specific conditions or local access for exploitation. A patch is available and can be applied during standard maintenance windows.
Apply vendor patch during routine maintenance. Standard security controls provide adequate interim protection.
Threat Intelligence Overview
NVD
CVE.org
EPSS
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
Denial of Service attacks render applications or systems unavailable by overwhelming resources or triggering failure conditions.
Affected Products (CPE)GitHub Advisory
All versions of @fastify/oauth2 used a statically generated state parameter at startup time and were used across all req
A redirect vulnerability in the `fastify-static` module version >= 4.2.4 and < 4.4.1 allows remote attackers to redirect
Fastify is a fast and low overhead web framework, for Node.js. Rated high severity (CVSS 7.5), this vulnerability is rem
Prototype pollution vulnerability in fastify-multipart < 1.0.5 allows an attacker to crash fastify applications parsing
Fastify node module before 0.38.0 is vulnerable to a denial-of-service attack by sending a request with "Content-Type: a
A denial of service vulnerability exists in Fastify v2.14.1 and v3.0.0-rc.4 that allows a malicious user to trigger reso
A redirect vulnerability in the fastify-static module version < 4.2.4 allows remote attackers to redirect users to arbit
Authorization bypass in the @fastify/express middleware-compatibility plugin (versions 4.0.6 and earlier) lets unauthent
Authentication bypass in @fastify/express v4.0.4 and earlier allows remote unauthenticated attackers to access protected
Middleware bypass in Fastify Express plugin (fastify/express) allows complete circumvention of authentication, authoriza
Fastify is a web framework with minimal overhead and plugin architecture. Rated high severity (CVSS 8.8), this vulnerabi
Authentication and authorization bypass in @fastify/middie (Node.js middleware library for Fastify) allows remote unauth
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