What’s Vulnerable › Vulnerabilities

CVE-2025-69211: Nest has a Fastify URL Encoding Middleware Bypass (TOCTOU)

• Severity: high (CVSS 7.4 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2025-12-29 · updated 2026-10-07
• Weakness: CWE-367

Description

Nest is a framework for building scalable Node.js server-side applications. Versions prior to 11.1.11 have a Fastify URL encoding middleware bypass. A NestJS application is vulnerable if it uses `@nestjs/platform-fastify`; relies on `NestMiddleware` (via `MiddlewareConsumer`) for security checks (authentication, authorization, etc.), or through `app.use()`; and applies middleware to specific routes using string paths or controllers (e.g., `.forRoutes('admin')`). Exploitation can result in unauthenticated users accessing protected routes, restricted administrative endpoints becoming accessible to lower-privileged users, and/or middleware performing sanitization or validation being skipped. This issue is patched in `@nestjs/platform-fastify@11.1.11`.

Affected products

• nestjs nest: before 11.1.11 — fixed in 11.1.11

How to fix

Upgrade to a fixed version: nestjs nest 11.1.11. Check the vendor advisory for mitigations.

References

• https://github.com/nestjs/nest/commit/c4cedda15a05aafec1e6045b36b0335ab850e771
• https://github.com/nestjs/nest/security/advisories/GHSA-8wpr-639p-ccrj

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