Description
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 tokens for sensitive Server Actions, prefer `SameSite=Strict` on sensitive auth cookies, and/or do not allow `'null'` in `serverActions.allowedOrigins` unless intentionally required and additionally protected.
INFO
Published Date :
2026-03-17T23:59:22.600Z
Last Modified :
2026-03-18T19:48:04.820Z
Source :
GitHub_M
AFFECTED PRODUCTS
The following products are affected by CVE-2026-27978 vulnerability.
| Vendors | Products |
|---|---|
| Vercel |
|
REFERENCES
Here, you will find a curated list of external links that provide in-depth information to CVE-2026-27978.
