Official Clerk JavaScript SDKs: Middleware-based route protection bypass_CVE-2026-41248

9.1 / 10

CRITICAL

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Description

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

AI Analysis

Middleware-based route protection bypass vulnerability in Clerk JavaScript SDKs

Basic Information

ID CVE-2026-41248

Source GitHub_M

Published Apr 24, 2026 at 21:04

Affected Product

Vendor clerk

Product astro

Version >= 0.0.1, < 1.5.7

Affected Versions clerk astro >= 0.0.1, < 1.5.7
clerk astro >= 2.0.0-snapshot.v20241206174604, <= 2.17.9
clerk astro >= 3.0.0, < 3.0.15
clerk nextjs >= 5.0.0, < 5.7.6
clerk nextjs >= 6.0.0-snapshot.vb87a27f, < 6.39.2
clerk nextjs >= 7.0.0, < 7.2.1
clerk nuxt >= 1.1.0, < 1.13.28
clerk nuxt >= 2.0.0, < 2.2.2
clerk shared >= 2.20.17, < 2.22.1
clerk shared >= 3.0.0-canary.v20250225091530, < 3.47.4
clerk shared >= 4.0.0, < 4.8.1

CWE Classification

CWE-436 CWE-863

AI Assessment

AI Score 9.1 / 10

AI Severity Critical

Vendor Clerk

Product Clerk JavaScript SDKs

Version <= 1.5.7, <= 2.17.9, <= 3.0.15, <= 5.7.6, <= 6.39.2, <= 7.2.1, <= 1.13.28, <= 2.2.2, <= 2.22.1, <= 3.47.4, <= 4.8.1

References

github.com /clerk/javascript/security/advisories/GHSA-vqx2-fgx2-5wq9

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