Origin Validation Error Affecting next package, versions >=16.0.0 <16.3.8
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-JS-NEXT-20569645
- published8 Oct 2026
- disclosed7 Oct 2026
- creditUnknown
Introduced: 7 Oct 2026
NewCVE-2026-94486 (opens in a new tab)How to fix?
Upgrade next to version 16.3.8 or higher.
Overview
next is a react framework.
Affected versions of this package are vulnerable to Origin Validation Error via the MCP middleware (get-mcp-middleware.ts) and the cross-site dev request blocker (block-cross-site-dev.ts), which fail to adequately validate the request origin against the host. An attacker who controls a DNS record can rebind a malicious domain to the victim's localhost address, causing the victim's browser to issue cross-origin requests to the local Next.js development server that bypass the intended origin checks, resulting in limited confidentiality and integrity impact.