Auth bypass in Astro \@Astrojs\/vercel
CVE-2026-33768
Astro is a web framework. Prior to version 10.0.2, the @astrojs/vercel serverless entrypoint reads the x-astro-path header and x_astro_path query parameter to rewrite the internal request path, with no authentication whatsoever. On deployments without Edge Middleware, this lets anyone bypass Vercel's platform-level path restrictions entirely. The override preserves the original HTTP method and body, so this isn't limited to GET. POST, PUT, DELETE all land on the rewritten path. A Firewall rule blocking /admin/* does nothing when the request comes in as POST /api/health?x_astro_path=/admin/delete-user. This issue has been patched in version 10.0.2.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N.
EPSS exploit prediction
EPSS: 0.005 (41.4th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 41st percentile — 41.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.005 · change: +0.002
Affected products
- Astro \@Astrojs\/vercel
- Withastro Astro — versions < 10.0.2
Weakness classification (CWE)
References
- github.com/withastro/astro/security/advisories/GHSA-mr6q-rp88-fx84 (Exploit, Vendor Advisory)
- github.com/withastro/astro/pull/15959 (Issue Tracking)
- github.com/withastro/astro/commit/335a204161f5a7293c128db570901d4f8639c6ed (Patch)
- github.com/withastro/astro/releases/tag/@astrojs/vercel@10.0.2 (Release Notes)
Frequently asked questions
- What is CVE-2026-33768?
- CVE-2026-33768 is a medium-severity vulnerability in Astro \@Astrojs\/vercel, classified under Unintended Proxy or Intermediary (Confused Deputy). CVSS score: 6.5/10. Published 2026-03-24.
- How severe is CVE-2026-33768?
- Medium severity. CVSS v3 base score is 6.5 out of 10.