React2Shell: A Critical Bug in React Server Components

December 20, 2025 (1w ago)

Recently, a major security issue was disclosed in React Server Components, known as React2Shell (CVE-2025-55182).
This bug was given the highest possible severity rating because it allowed remote code execution on servers without any authentication. :contentReference[oaicite:3]{index=3}

The bug affected the way server payloads were deserialized in React’s Server Components "Flight" protocol. The flaw meant that a crafted HTTP request could cause the server to run arbitrary, attacker-controlled code. :contentReference[oaicite:4]{index=4}


Why This Bug Was Dangerous

The vulnerability was especially concerning because:

Shortly after the public disclosure, threat intelligence teams observed active scanning and exploitation attempts for this vulnerability. :contentReference[oaicite:6]{index=6}


How the Community Responded

The React team and framework maintainers released patched versions within days of the disclosure.
Developers were strongly advised to upgrade to the fixed releases immediately to prevent attackers from exploiting the issue. :contentReference[oaicite:7]{index=7}

React Server Components remain a powerful feature, but this incident reminded the community that complex server-side features carry risk if not maintained and audited carefully.


What I Learned from This

Writing real production apps taught me that:

This React2Shell bug was a reminder that even widely-trusted tools like React can have serious issues — and developers must stay alert.