cvedb.io
CVE-2026-27978
MEDIUM · CVSS 4.3
EPSS exploitation probability: 0%
Published 2026-03-18T00:16:20.117 · Last modified 2026-06-17T10:28:00.450

Summary

Next.js is a React framework for building full-stack web applications. Starting in version 16.0.1 and prior to version 16.1.7, `origin: null` was treated as a "missing" origin during Server Action CSRF validation. As a result, requests from opaque contexts (such as sandboxed iframes) could bypass origin verification instead of being validated as cross-origin requests. An attacker could induce a victim browser to submit Server Actions from a sandboxed context, potentially executing state-changing actions with victim credentials (CSRF). This is fixed in version 16.1.7 by treating `'null'` as an explicit origin value and enforcing host/origin checks unless `'null'` is explicitly allowlisted in `experimental.serverActions.allowedOrigins`. If upgrading is not immediately possible, add CSRF toke

Affected products

vercel — next.js

Does this affect you?

Add your gear to cvedb and we'll alert you only when vercel ships something exploited.

Check my exposure →

References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.