What Is CVE-2025-55182 (React2Shell)?

React2Shell – Why It Matters

Developers use React to build modern websites.  A new feature called React Server Components makes websites faster by doing work on the server. However, security experts found a huge issue in this tool. This vulnerability is known as CVE-2025-55182, also referred to as React2Shell. The problem is extremely severe since it enables hackers to gain control of a server.

Hackers do not need a password to attack. They just leave a special message on the site. The server reads this message and makes a mistake. This error allows the hacker to run his own code. Security teams have to respond quickly to rectify this. This guide describes the facts about the risk.

Meaning Of CVE-2025-55182 (React2Shell)

The name CVE-2025-55182 refers to a specific security hole. The professionals discovered it in the React software library. It is an unauthenticated remote code execution vulnerability. This means that a stranger can run commands on your server even when they are far. Also, there is no need to log in.

React has a system known as the Flight protocol. This system transmits data between the user and the server. The server turns this data back into objects. This is referred to as deserialization. The React2Shell vulnerability occurs as the server trusts the data too much. A hacker can hide a virus inside this data. The server processes the virus and provides the hacker with full power.

Technical Features

How The Flight Protocol Fails

The Flight protocol is the foundation of the modern React apps. It transfers information in small bits known as chunks.

The Problem With Data Chunks

These chunks are given to the server to build a web page. It has to fit these pieces together in the correct sequence. The software fails to verify whether the pieces are safe. Well, a hacker can send a piece that appears like a regular part of the app. The server accepts this fake piece without asking questions. This is a huge logic error in the code.

Prototype Pollution Risks

JavaScript has a system called prototypes to share features among objects. The React2Shell attack involves a technique known as prototype pollution. The hacker transmits data that changes how the server works. They target internal components of the JavaScript engine. Such a change enables the hacker to access parts of the server they should not see. It opens a door for the next step of the attack.

Remote Code Execution

The last objective of the hacker is code execution. They use the polluted objects to trigger commands. The server begins to run the hacker’s scripts. Such scripts are able to destroy files or steal data. The hacker gains the same power as the web server itself. They can now explore the whole computer system.

Real World Impact Of CVE-2025-55182 On Cloud Security

Cloud servers are used by many businesses to host their applications. According to recent statistics, this flaw is extremely prevalent.

Wiz Research Statistics

Wiz Research researched numerous cloud systems. They discovered that 39 percent of cloud environments are vulnerable. This is an extremely large figure for a single fault. Many apps use the Next.js framework. Next.js utilizes the vulnerable React code by default. Approximately 44 percent of all cloud environments have a Next.js application facing the internet.

Observed Attacks

In December 2025, Hackers started exploiting this vulnerability. They use it to steal cloud keys. These keys provide them access to private data. Some hackers install software to mine digital money. This makes the server slow and costly. Other groups take advantage of the loophole to install permanent spyware. They want to remain within the server long time.

Vulnerable Versions List

The vulnerability affects React 19.0.0-19.2.0. It also strikes Next.js 15 and 16. Any application that has the App Router feature may be vulnerable to attack. Although a developer did not write bad code, it is the framework itself is the problem. This makes the flaw very dangerous for everyone.

Security Features Of Cantech Hosting

You need a safe place to host your website. Cantech provides tools to help protect your data.

Advanced DDoS Protection

Cantech has a powerful network attack shield. It prevents heavy traffic from hitting your server. This keeps your website online during an attack.

Malware Scanning Tools

The system checks your files for bad scripts every day. It identifies viruses before they cause any damage. This is a key layer of safety for your apps.

Firewall Protection

You have a digital wall in front of your hosting. It prevents numerous hacking attacks. You can establish regulations to permit safe traffic only.

Daily Backups

Cantech saves a copy of your site every day. You can restore your data if a hacker breaks something. 

24/7 Expert Support

The technical team is always ready to help. They will be able to guide you on how to upgrade your software. You can reach them at any hour.

How To Protect Your Website from CVE-2025-55182 (React2Shell)

This is something that you need to correct today. There is only one way to stay safe.

Update Your Software

You need to install the recent version of React. The fix is 19.2.1 and newer versions. You also need to upgrade Next.js to the latest patch. This removes the bad code from your system. It is the most appropriate method of preventing the React2Shell attack. Do not wait to run these updates.

Check Your Logs

Check the web server logs for unusual requests. Be alert to messages that seem to be broken code. These could be unsuccessful attack attempts. In case you find them, you need to look into it. Ask whether there were any new files on your server. It is also good to change your passwords after an update.

Conclusion

The React2Shell flaw is a major threat to the internet. It permits complete password-free control of servers. There are thousands of websites that are at risk right now. You must check your React and Next.js versions immediately. Using a secure host like Cantech helps add extra layers of safety. The best way to keep off hackers is to keep up to date. Patch your systems today to keep your data private.

FAQs

What is the main cause of the React2Shell flaw?

The defect is due to an error in the Flight protocol. This protocol handles how React sends data. The server fails to authenticate the chunks of data correctly. Hackers take advantage of this and execute their commands. It is a logical error of the deserialization process.

Do I have to repair CVE-2025-55182 (React2Shell) if I do not use Server Functions?

Yes, you still need to fix it. The default setup includes vulnerable code. Any application that employs the App Router is at risk. The server processes the bad data before it checks your code. Even with a simple website, you are in danger.

How do I know my server was hacked?

Check for high CPU usage on your server. Hackers usually execute money-mining scripts, which consume high power. Find new files in your folders. Check your environment variables for changes. Unusual network traffic is also a sign of a breach.

Is there a temporary fix for React2Shell besides updating?

Certain web filters have the capability of blocking known attack patterns. These are referred to as Web Application Firewalls. They might stop some hackers. Nevertheless, they cannot be an ultimate solution. To be really safe, you need to upgrade your React version.

Which frameworks are affected by CVE-2025-55182 (React2Shell)?

Next.js is the most common framework at risk. The bad code is also used in other tools such as Waku and RedwoodJS. The flaw is in any tool that includes the react-server package. You should check the update notes for every tool you use.