vercel next.js up to 16.1.6 cross-site request forgery

Summaryinfo

A vulnerability, which was classified as problematic, has been found in vercel next.js up to 16.1.6. This issue affects some unknown processing. The manipulation leads to cross-site request forgery. This vulnerability is listed as CVE-2026-27978. The attack may be initiated remotely. There is no available exploit. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in vercel next.js up to 16.1.6. This issue affects an unknown functionality. The manipulation with an unknown input leads to a cross-site request forgery vulnerability. Using CWE to declare the problem leads to CWE-352. The web application does not, or can not, sufficiently verify whether a well-formed, valid, consistent request was intentionally provided by the user who submitted the request. Impacted is integrity. The summary by CVE is:

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.

It is possible to read the advisory at github.com. The identification of this vulnerability is CVE-2026-27978 since 02/25/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. It demands that the victim is doing some kind of user interaction. The technical details are unknown and an exploit is not publicly available.

The vulnerability scanner Nessus provides a plugin with the ID 303199 (Next.js Framework 16.0.1 < 16.1.7 Multiple Vulnerabilities), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 16.1.7 eliminates this vulnerability. The upgrade is hosted for download at github.com. Applying the patch a27a11d78e748a8c7ccfd14b7759ad2b9bf097d8 is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at Tenable (303199). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Type

• JavaScript Library

Vendor

• vercel

Name

• next.js

Version

• 16.1.0
• 16.1.1
• 16.1.2
• 16.1.3
• 16.1.4
• 16.1.5
• 16.1.6

License

• open-source

Website

• Product: https://github.com/vercel/next.js/

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Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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