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.
{
"cna_assigner": "GitHub_M",
"cwe_ids": [
"CWE-352"
],
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/27xxx/CVE-2026-27978.json"
}{
"extracted_events": [
{
"cpe": "cpe:2.3:a:vercel:next.js:*:*:*:*:*:node.js:*:*",
"range": [
{
"introduced": "16.0.1"
},
{
"fixed": "16.1.7"
}
],
"source": "CPE_RANGE"
},
{
"range": [
{
"fixed": "a27a11d78e748a8c7ccfd14b7759ad2b9bf097d8"
}
],
"source": "REFERENCES_COMMIT"
},
{
"original_tag": "v16.1.7",
"range": [
{
"fixed": "bdf3e3577a6d55ea186a48238d61fbd8da07a626"
}
],
"source": "REFERENCES_TAG"
}
]
}