CVE-2026-54281
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedNest is a framework for building scalable Node.js server-side applications. Prior to 11.1.24, an authentication bypass vulnerability exists in @nestjs/platform-fastify. When middleware is registered through NestJS's MiddlewareConsumer.forRoutes() API on the Fastify adapter, an unauthenticated client can bypass the Nest middleware registered for that route by simply appending a trailing slash (/) to the request URL. This bypass works on the default Fastify adapter configuration. This vulnerability is fixed in 11.1.24.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceAn authentication bypass vulnerability exists in @nestjs/platform-fastify where middleware registered through NestJS's MiddlewareConsumer.forRoutes() API can be circumvented by adding a trailing slash (/) to the request URL. This affects the default Fastify adapter configuration, allowing unauthenticated access to protected routes.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- Low
- Authentication
- X
- User interaction
- None
- Scope
- X
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Check installed version of @nestjs/platform-fastifyRun 'npm list @nestjs/platform-fastify' or inspect the dependencies in your package.json fileAffected if The installed version is lower than 11.1.24
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Verify Fastify adapter is in useInspect your main.ts bootstrap file and look for FastifyAdapter or FastifyHttpAdapter being passed to NestFactory.create()Affected if Your application uses FastifyAdapter for serving the NestJS application
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Confirm MiddlewareConsumer.forRoutes() is used for middlewareSearch your codebase for MiddlewareConsumer imported from @nestjs/common and used with .forRoutes() method to register middleware on protected endpointsAffected if You have middleware registered via MiddlewareConsumer.forRoutes() applied to routes that should require authentication
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Test for trailing slash bypassSend a test request to a protected endpoint without a trailing slash (e.g., GET /api/resource), then repeat with a trailing slash (GET /api/resource/). Compare the responses.Affected if The request with trailing slash returns a successful response (200 or expected data) while the same request without trailing slash returns an authentication error (401 or redirects to login)
You are affected if you are using @nestjs/platform-fastify version below 11.1.24 with the Fastify adapter and have authentication middleware registered via MiddlewareConsumer.forRoutes() that can be bypassed using a trailing slash in the request URL.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scopedUpgrade @nestjs/platform-fastify to version 11.1.24 or later to remediate this vulnerability.
@nestjs/platform-fastify version 11.1.24
- Update the @nestjs/platform-fastify package to version 11.1.24 or later by running: npm install @nestjs/platform-fastify@^11.1.24
- Verify the update was successful by checking the installed version: npm list @nestjs/platform-fastify
- Test the application to confirm the middleware bypass vulnerability is resolved and that the trailing slash no longer allows bypassing authentication middleware
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation1.0 h
- Implementation1.0 h
- Testing2.0 h
- Review / QA1.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2026-54281 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-54281 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
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