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Researchers have found two new vulnerabilities in React Server Components while attempting to exploit the patches last week. These are new issues, separate from the critical CVE last week. The patch for React2Shell remains effective for the Remote Code Execution exploit.

We disclosed two new RSC vulnerabilities: - Denial of Service (High): CVE-2025-55184 - Source Code Exposure (Medium): CVE-2025-55183 Patches are available now, please update immediately. react.dev/blog/2025/12...

It’s common for critical CVEs to uncover follow‑up vulnerabilities. When a critical vulnerability is disclosed, researchers scrutinize adjacent code paths looking for variant exploit techniques to test whether the initial mitigation can be bypassed.

This pattern shows up across the industry, not just in JavaScript. For example, after Log4Shell, additional CVEs were reported as the community examined the original fix. Additional disclosures can be frustrating, but they are generally a sign of a healthy response cycle.

These issues are present in the patches published last week for React2Shell. Even though they do not allow for Remote Code Execution they are high severity and you should update (again) immediately. react.dev/blog/2025/12...