Understanding CVE-2025-55184 and CVE-2025-55183: Secure Your React Applications

In December 2025, React disclosed two critical vulnerabilities, CVE-2025-55184 and CVE-2025-55183, affecting React Server Components and requiring immediate patching for Next.js applications using App Router. CVE-2025-55184, with a CVSS score of 7.5, facilitates denial of service through unsafe deserialization, while CVE-2025-55183, with a CVSS score of 5.3, exposes server function source code. These vulnerabilities affect React versions 19.0.0 to 19.2.1 and Next.js versions 13.x to 16.x, with no workarounds available, necessitating upgrades to React versions 19.0.3+, 19.1.4+, or 19.2.3+ and Next.js versions 14.2.35+, 15.0.7+, or 16.0.10+. Although Strapi CMS is unaffected, developers using it with Next.js need to patch their frontends to prevent exploitation. The document emphasizes the need for immediate patching, verification of applied patches, and the implementation of security best practices to prevent similar issues, such as storing secrets in environment variables and integrating automated security scans into CI/CD pipelines.