Urgent: Critical RCE Vulnerability in React Server Components – Patch Immediately!

Overview

A critical pre-authentication remote code execution (RCE) vulnerability, identified as CVE-2025-55182, has been discovered in React Server Components (RSC). This vulnerability affects versions 19.0.0, 19.1.0, 19.1.1, and 19.2.0, specifically within the react-server-dom-parcel, react-server-dom-turbopack, and react-server-dom-webpack packages. Successful exploitation of this vulnerability allows an attacker to execute arbitrary code on the server without authentication.

Given the ease of exploitation and potential impact, immediate action is required to mitigate this risk.

Technical Details

The vulnerability stems from the unsafe deserialization of payloads received from HTTP requests directed to Server Function endpoints. The affected versions of React Server Components inadequately sanitize or validate incoming data during deserialization, allowing an attacker to inject malicious code within the serialized payload. This injected code is then executed by the server when the payload is processed.

The pre-authentication nature of this vulnerability makes it particularly dangerous, as no prior authentication or authorization is required for exploitation.

CVSS Analysis

This vulnerability has been assigned a CVSS score of 10, indicating its critical severity. A CVSS score of 10 represents the most severe type of vulnerability with the highest potential impact.

• CVE ID: CVE-2025-55182
• Severity: CRITICAL
• CVSS Score: 10

Possible Impact

Exploitation of CVE-2025-55182 can lead to severe consequences, including:

• Complete server compromise: Attackers can gain full control of the affected server.
• Data breach: Sensitive data stored on the server may be exposed or stolen.
• Service disruption: Attackers can disrupt or completely shut down the affected application or service.
• Malware deployment: The compromised server can be used to distribute malware to other systems.

Mitigation and Patch Steps

The most effective mitigation is to upgrade to a patched version of React Server Components that addresses this vulnerability. Follow these steps:

1. Upgrade React and Related Packages: Upgrade to a version of React Server Components that is *not* within the vulnerable range (19.0.0, 19.1.0, 19.1.1, and 19.2.0). Refer to the official React blog for the specific patched versions.
2. Verify Package Versions: After upgrading, verify that the react-server-dom-parcel, react-server-dom-turbopack, and react-server-dom-webpack packages are updated to the patched versions.
3. Monitor for Suspicious Activity: Implement robust monitoring and logging to detect any suspicious activity that may indicate an attempted exploitation.
4. Review Server Function Endpoints: Review your Server Function endpoints to ensure they are not inadvertently exposing sensitive data or functionality.

Note: Always refer to the official React documentation and security advisories for the most up-to-date information and patching instructions.

References

React Blog: Critical Security Vulnerability in React Server Components
Facebook Security Advisory: CVE-2025-55182