Cloudflare Outage Triggered by Urgent React2Shell Patch Implementation
Earlier today, Cloudflare faced a significant outage that disrupted websites and online services globally. Users encountered a “500 Internal Server Error” when trying to access various platforms.
Cause of the Outage: Urgent React2Shell Patch
In an update on their status page, Cloudflare attributed the incident to an emergency patch implemented to address a critical vulnerability in React Server Components. This vulnerability, tracked as CVE-2025-55182 and known as React2Shell, poses remote code execution risks. It has been actively exploited in some cyberattacks.
According to Cloudflare, a modification in how their Web Application Firewall processes requests rendered their network unavailable for several minutes this morning. The company clarified that this was not a malicious attack, but rather a necessary action to mitigate the recently disclosed industry-wide vulnerability.
Details of the React2Shell Vulnerability
- Vulnerability Type: Remote code execution
- Affected Frameworks: React, Next.js, React Router, and several others
- Impact: Allows unauthenticated attackers to execute code via malicious HTTP requests
- Affected Versions: React versions 19.0, 19.1.0, 19.1.1, and 19.2.0
The flaw was identified in the React Server Components ‘Flight’ protocol. It affects multiple React packages that are configured by default, increasing the urgency for developers to apply necessary updates.
Current Exploitation Efforts
Despite the outage not being as widespread as initially feared, security experts from Amazon Web Services (AWS) have reported that several hacking groups linked to China, including Earth Lamia and Jackpot Panda, are exploiting the React2Shell vulnerability. These attacks began mere hours after the vulnerability was disclosed.
The NHS England National Cyber Security Operations Centre has also raised concerns, stating that several functional exploits for CVE-2025-55182 are already available. They warned that further exploitation is highly likely.
This recent incident follows another significant outage for Cloudflare last month, which affected their Global Network for nearly six hours, described by CEO Matthew Prince as the worst incident since 2019.
Previously, Cloudflare dealt with a major outage in June that generated Access authentication failures and connectivity issues across various regions, affecting infrastructures, including Google Cloud.
Conclusion
As Cloudflare navigates these challenges, it reinforces the critical importance of cybersecurity in maintaining reliable online services. Users and developers alike are encouraged to stay vigilant and apply updates to their systems promptly to mitigate the risks posed by such vulnerabilities.
