## Critical RCE Vulnerability in React Server Components Exposes Next.js Deployments via Insecure Deserialization
A critical remote code execution vulnerability in React Server Components has been identified, enabling unauthenticated attackers to execute arbitrary code on servers running affected deployments. The flaw resides in insecure deserialization handling within the React Flight protocol, which several major frameworks—including Next.js—rely upon for server-side rendering operations. Vercel issued an automatic pull request targeting the project sam-web-porto to patch the exposure, though officials caution the automated fix may not be comprehensive and could contain errors.

The vulnerability is tracked under three separate advisories: GitHub Security Advisory GHSA-9qr9-h5gf-34mp, React Advisory CVE-2025-55182, and Next.js Advisory CVE-2025-66478. The disclosure affects any deployment leveraging React Server Components through Vercel's infrastructure or compatible frameworks. The attack surface exists specifically where untrusted data reaches the React Flight deserialization pipeline without sufficient validation, allowing adversaries to craft payloads that bypass authentication and achieve code execution on the host system.

Security teams are urged to review the Vercel guidance before applying the automated changes and to conduct manual verification of any Flight protocol data handling within their applications. The overlap between multiple CVEs across the React and Next.js ecosystems suggests the underlying issue spans component libraries and deployment tooling, raising the risk profile for organizations with sprawling server-component architectures. Continued monitoring for additional affected frameworks and downstream patches is warranted.
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- **Source**: GitHub Issues
- **Sector**: The Lab
- **Tags**: react, nextjs, rce, vercel, cve
- **Credibility**: unverified
- **Published**: 2026-04-29 06:54:11
- **ID**: 78109
- **URL**: https://whisperx.ai/en/intel/78109