CVEvulnerability
CVE-2026-27978
5.3 MEDIUM
Official page ↗
- Status
- Analyzed
- Published
- 2026-03-18
- Last modified
- 2026-06-17
- Assigner
- [email protected]
- CVSS 4.0 ([email protected])
- 5.3 MEDIUM — CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
- CVSS 3.1 ([email protected])
- 4.3 MEDIUM — CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
- Weaknesses
- CWE-352
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.
Affected configurations
• vercel next.js (>= 16.0.1 < 16.1.7)
Related
Weakness · CWE (1)
- CWE-352 Cross-Site Request Forgery weakness