medium

CVE-2026-64643

npm · next

Summary

Next.js: Unauthenticated disclosure of internal Server Function endpoints

Severity
medium
EPSS
0.5% (p43)
CWE
CWE-201
Also known as
GHSA-955p-x3mx-jcvp
Published
2026-07-22
Updated
2026-07-22

Advisory details

Impact

In 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 + Server Actions.

By itself, this disclosure is typically a recon/enumeration primitive; however, it can increase risk when combined with other weaknesses.

Workarounds

Never assume any authentication claims at the use cache or use server boundary. Always authenticate within the boundary.

References

Related advisories

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Sources: CISA KEV (public domain), OSV.dev & GitHub Advisory Database (CC-BY-4.0), FIRST EPSS, NVD/CWE (public domain). Served live from the Stateward advisory database.