Vulnerability Description
Next.js is a React framework for building full-stack web applications. In versions 12.0.0 through 15.5.20 and 16.0.0 through 16.2.10, Next.js applications using App Router, Server Actions (use server) or use cache endpoints can be disclosed bypassing any authentication on the pages where these endpoints are usually used. Server Action IDs can be disclosed to unauthenticated users via publicly served client artifacts (for example, static chunks containing action references). Affected users are applications using App Router and Server Actions. By itself, this disclosure is typically a recon/enumeration primitive; however, it can increase risk when combined with other weaknesses. This issue has been fixed in versions 15.5.21 and 16.2.11.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Vercel | Next.Js | >= 13.0.0, < 15.5.21 |
Related Weaknesses (CWE)
References
- https://github.com/vercel/next.js/commit/1b0c3ae912a3ad925c60065cc8d55b070fa8bcdPatch
- https://github.com/vercel/next.js/commit/ff12a6124e1504f17b62de948b8a553fdecaef7Patch
- https://github.com/vercel/next.js/releases/tag/v15.5.21ProductRelease Notes
- https://github.com/vercel/next.js/releases/tag/v16.2.11ProductRelease Notes
- https://github.com/vercel/next.js/security/advisories/GHSA-955p-x3mx-jcvpVendor Advisory
FAQ
What is CVE-2026-64643?
CVE-2026-64643 is a vulnerability with a CVSS score of 5.3 (MEDIUM). Next.js is a React framework for building full-stack web applications. In versions 12.0.0 through 15.5.20 and 16.0.0 through 16.2.10, Next.js applications using App Router, Server Actions (use server)...
How severe is CVE-2026-64643?
CVE-2026-64643 has been rated MEDIUM with a CVSS base score of 5.3/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-64643?
Check the references section above for vendor advisories and patch information. Affected products include: Vercel Next.Js.