Auth bypass in Clerk Astro

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 re…

EPSS: 0.001 (26.5th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N.

Affected products

  • Clerk Astro — versions >= 0.0.1, < 1.5.7, >= 2.0.0-snapshot.v20241206174604, <= 2.17.9, >= 3.0.0, < 3.0.15
  • Clerk Nextjs — versions >= 5.0.0, < 5.7.6, >= 6.0.0-snapshot.vb87a27f, < 6.39.2, >= 7.0.0, < 7.2.1
  • Clerk Nuxt — versions >= 1.1.0, < 1.13.28, >= 2.0.0, < 2.2.2
  • Clerk Shared — versions >= 2.20.17, < 2.22.1, >= 3.0.0-canary.v20250225091530, < 3.47.4, >= 4.0.0, < 4.8.1

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-41248?
CVE-2026-41248 is a critical-severity vulnerability in Clerk Astro, classified under CWE-436. CVSS score: 9.1/10. Published 2026-04-24.
How severe is CVE-2026-41248?
Critical severity. CVSS v3 base score is 9.1 out of 10.