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Vulnerability record · CVE-2021-22963 · published 14 October 2021

CVE-2021-22963: Fastify-static open redirect vulnerability

Fastify · Fastify Static

A redirect vulnerability in the fastify-static module version < 4.2.4 allows remote attackers to redirect users to arbitrary websites via a double slash // followed by a domain: http://localhost:3000//google.com/%2e%2e.The issue shows up on all the fastify-static applications that set redirect: true option. By default, it is false.

6.1 CVSS 3.1 Medium EPSS 1.2% · top 33.9% CWE-601 · Open redirect
6.1CVSS 3.1 base score, v2 5.8
1.2%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
2References, 2 tagged exploit
17 Jun 2026Last modified by NVD

Description

A redirect vulnerability in the fastify-static module version < 4.2.4 allows remote attackers to redirect users to arbitrary websites via a double slash // followed by a domain: http://localhost:3000//google.com/%2e%2e.The issue shows up on all the fastify-static applications that set redirect: true option. By default, it is false.

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://hackerone.com/reports/1354255 ExploitIssue TrackingThird Party Advisory
https://hackerone.com/reports/1354255 ExploitIssue TrackingThird Party Advisory

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

8.8CVE-2021-22964Fastify-static uncontrolled resource consumption vulnerabilityA redirect vulnerability in the `fastify-static` module version >= 4.2.4 and < 4.4.1 allows remote attackers to redirect Mozilla Firefox users to arb…EPSS 1.0%7.5CVE-2026-18427Fastify-static path traversal vulnerability@fastify/static before version 10.1.3 contains an incomplete fix for a previous route guard bypass. The static file handler rejected only parent dire…EPSS 0.66%7.5CVE-2026-15074Fastify-static path traversal vulnerability@fastify/static up to and including version 10.1.0 fails to reject dot-dot path segments in request pathnames before the file-resolution stage. This …EPSS 0.67%5.9CVE-2026-6414Fastify-static vulnerability@fastify/static versions 8.0.0 through 9.1.0 decode percent-encoded path separators (%2F) before filesystem resolution, while Fastify's router treats…EPSS 0.45%5.3CVE-2026-7120Fastify-static vulnerability@fastify/static evaluates the allowedPath callback before normalizing dot segments and duplicate path separators in the pathname used for file resolu…EPSS 0.37%5.3CVE-2026-6410Fastify-static path traversal vulnerability@fastify/static versions 8.0.0 through 9.1.0 allow path traversal when directory listing is enabled via the list option. The dirList.path() function …EPSS 0.53%4.7CVE-2012-0518Oracle Fusion Middleware SSO open redirect flawOracle Fusion Middleware 10.1.4.3.0 contains an unspecified open redirect vulnerability in the Application Server Single Sign-On component, tracked a…KEVEPSS 4.7%analysed6.1CVE-2021-38000Google Chrome Android Intents input validation open redirectChrome on Android before 95.0.4638.69 fails to properly validate untrusted input passed through Intents, allowing a crafted HTML page to redirect the…KEVEPSS 4.9%analysed

Source: NIST National Vulnerability Database (record CVE-2021-22963), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.