EUVD-2026-293134

fkie_cve-2026-41248

Clerk JavaScript is the official JavaScript repository for Clerk authentication. createRouteMatcher in @clerk/nextjs, @clerk/nuxt, and @clerk/astro can be bypassed by certain crafted requests, allowing them to skip middleware gating and reach downstream handlers. This vulnerability is fixed in @clerk/astro 1.5.7, 2.17.10, and 3.0.15; @clerk/nextjs 5.7.6, 6.39.2, and 7.2.1; @clerk/nuxt 1.13.28 and 2.2.2; and @clerk/shared 2.22.1, 3.47.4, anc 4.8.1

GHSA-vqx2-fgx2-5wq9 — Official Clerk JavaScript SDKs: Middleware-based route protection bypass

Affected: npm: @clerk/nextjs, npm: @clerk/nuxt, npm: @clerk/astro, npm: @clerk/shared

## Summary

`createRouteMatcher` in `@clerk/nextjs`, `@clerk/nuxt`, and `@clerk/astro` can be bypassed by certain crafted requests, allowing them to skip middleware gating and reach downstream handlers.

Sessions are not compromised and no existing user can be impersonated - the bypass only affects the middleware-level gating decision.

## Who is affected

All apps using `createRouteMatcher` should upgrade to the patched versions. Patches are drop-in with no API changes. The information below describes the scope of the bypass and helps you understand whether you are potentially affected, but is not a reason to delay the upgrade.

Apps relying only on middleware gating via `createRouteMatcher` are affected, because a crafted request can skip middleware checks and reach downstream handlers (API routes, server components, etc.). This middleware pattern permits the bypass:

```ts // Next.js example, equivalent patterns exist in Nuxt and Astro const isProtectedRoute = createRouteMatcher(['/admin(.*)']);

export default clerkMiddleware(async (auth, req) => { if (isProtectedRoute(req)) { await auth.protect(); } }); ```

That said, the bypass is limited to the middleware-level route-matching gate. `clerkMiddleware` still authenticates the request and `auth()` reflects the real authentication state of the caller. Auth checks performed inside your route handlers, server components, or server actions continue to work correctly and are not affected. Whether your app is affected…

Most recent entries from all

EUVD-2026-293134

fkie_cve-2026-41248

GHSA-vqx2-fgx2-5wq9 — Official Clerk JavaScript SDKs: Middleware-based route protection bypass