GHSA-vqx2-fgx2-5wq9
CRITICALGHSA-vqx2-fgx2-5wq9 is a critical-severity (CVSS 9.1) CWE-436 vulnerability in @clerk/nextjs. O3 Security confirms whether GHSA-vqx2-fgx2-5wq9 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Official Clerk JavaScript SDKs: Middleware-based route protection bypass
Blast Radius
@clerk/nextjs📦@clerk/nuxt📦@clerk/astro📦@clerk/shared📦@clerk/nextjs📦@clerk/nextjs📦@clerk/nuxt📦@clerk/astro+3 moreReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects npm packages — download data is not available via public APIs for these ecosystems.
Description
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:
// 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 in practice depends on whether you have those downstream checks.
External APIs that authenticate each request with a token are also unaffected on those endpoints, since token verification runs independently.
Additionally, this common middleware pattern correctly blocks the bypass at the middleware layer:
// Next.js example, equivalent patterns exist in Nuxt and Astro
const isPublicRoute = createRouteMatcher(['/docs(.*)']);
export default clerkMiddleware(async (auth, req) => {
if (!isPublicRoute(req)) {
await auth.protect();
}
});
@clerk/shared is usually not imported directly in application code, but if you import createPathMatcher from an affected @clerk/shared version, you are also affected. Run npm why @clerk/shared (or your package manager's equivalent) to check your installed version.
Recommended actions
Install the patched version for your framework (pick the one matching your current major):
@clerk/nextjs
- v7.x: fixed in
7.2.1 - v6.x: fixed in
6.39.2 - v5.x: fixed in
5.7.6
@clerk/nuxt
- v2.x: fixed in
2.2.2 - v1.x: fixed in
1.13.28
@clerk/astro
- v3.x: fixed in
3.0.15 - v2.x: fixed in
2.17.10 - v1.x: fixed in
1.5.7
@clerk/shared
- v4.x: fixed in
4.8.1 - v3.x: fixed in
3.47.4 - v2.x: fixed in
2.22.1
Workaround
If you cannot upgrade immediately, adding server-side auth checks (auth()) inside your route handlers, server components, or server actions provides defense-in-depth against this bypass.
Timeline
This issue was reported on 13 APR 2026, patched on 15 APR 2026, and publicly disclosed on 15 APR 2026.
Thanks to Christiaan Swiers for the responsible disclosure of this vulnerability.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @clerk/nextjs | ≥ 5.0.0&&< 5.7.6 | 5.7.6 |
| 📦npm | @clerk/nuxt | ≥ 1.1.0&&< 1.13.28 | 1.13.28 |
| 📦npm | @clerk/astro | ≥ 0.0.1&&< 1.5.7 | 1.5.7 |
| 📦npm | @clerk/shared | ≥ 2.20.17&&< 2.22.1 | 2.22.1 |
| 📦npm | @clerk/nextjs | ≥ 6.0.0-snapshot.vb87a27f&&< 6.39.2 | 6.39.2 |
| 📦npm | @clerk/nextjs | ≥ 7.0.0&&< 7.2.1 | 7.2.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @clerk/nextjs. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update @clerk/nextjs to 5.7.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-vqx2-fgx2-5wq9 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-vqx2-fgx2-5wq9 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-vqx2-fgx2-5wq9. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-vqx2-fgx2-5wq9 in your dependencies?
O3 detects GHSA-vqx2-fgx2-5wq9 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.