GHSA-vqx2-fgx2-5wq9 — @clerk/nextjs
CRITICALGHSA-vqx2-fgx2-5wq9 is a critical-severity (CVSS 9.1) CWE-436 vulnerability in @clerk/nextjs. A fix is available for @clerk/nextjs — see the affected versions and patch details below.
Official Clerk JavaScript SDKs: Middleware-based route protection bypass
Exploitation Status
No confirmed exploitation observed yet
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for GHSA-vqx2-fgx2-5wq9.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
GHSA-vqx2-fgx2-5wq9 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,636 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
@clerk/nextjsnpm@clerk/nuxtnpm@clerk/astronpmDescription
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 | 5.7.6npm install @clerk/nextjs@5.7.6 |
| 📦npm | @clerk/nuxt | ≥ 1.1.0&&< 1.13.28 | 1.13.28npm install @clerk/nuxt@1.13.28 |
| 📦npm | @clerk/astro | ≥ 0.0.1&&< 1.5.7 | 1.5.7npm install @clerk/astro@1.5.7 |
| 📦npm | @clerk/shared | ≥ 2.20.17&&< 2.22.1 | 2.22.1npm install @clerk/shared@2.22.1 |
| 📦npm | @clerk/nextjs | ≥ 6.0.0-snapshot.vb87a27f&&< 6.39.2 | 6.39.2npm install @clerk/nextjs@6.39.2 |
| 📦npm | @clerk/nextjs | ≥ 7.0.0&&< 7.2.1 | 7.2.1npm install @clerk/nextjs@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, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-vqx2-fgx2-5wq9 can be triaged on real exposure rather than presence alone.
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 Security finds GHSA-vqx2-fgx2-5wq9 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.