CVE-2025-55184 Scanner

React Server Components are utilized primarily in web applications to streamline rendering on the server side, providing developers with a robust way to manage large-scale applications efficiently. These components are often deployed within environments that leverage technologies like react-server-dom-parcel or react-server-dom-turbopack, facilitating fast dynamic content management. Organizations with substantial frontend user interactions depend heavily on React Server Components to enhance performance. By seamlessly integrating with client-side frameworks, these components significantly improve the user experience by enabling faster page loads and interactivity. Developers choose React Server Components for their ability to reduce the complexity of managing component states and for the increased efficiency in resource utilization. Deployed across various operating systems, these components are an integral part of modern web development structures.

The Denial of Service (DoS) vulnerability within React Server Components arises from unsafe payload deserialization. This flaw allows attackers to exploit server function endpoints, causing the server to hang indefinitely. Unauthenticated attackers can trigger this state, effectively blocking legitimate requests and rendering the application unresponsive. The vulnerability affects all component setups from version 19.0.0 through 19.2.1, impacting various technologies relying on React Server. Due to the critical role these components play in server reliability, the vulnerability poses a significant risk to application continuity. Attackers leveraging this vulnerability could lead to prolonged downtime and resource depletion.

The Denial of Service vulnerability is technically rooted in the insecure deserialization process of React Server Components' server function endpoints. Attackers craft specific payloads that exploit this deserialization flaw by submitting form data using a POST request. When processed, this data hangs the server operation, leaving it unable to respond to requests. The vulnerability is confirmed when responses include 404 status codes indicating "Server action not found," combined with specific content types. This flaw in deserialization represents a critical point of failure, allowing unauthenticated attackers ease of exploitation. Given its technical nature, identifying and mitigating this vulnerability requires updates to the deserialization logic beyond version 19.2.1.

Exploitation of this vulnerability by attackers can result in the server becoming entirely unavailable to legitimate users, disrupting service delivery. The indefinite hanging of server processes as designed by malicious actors leads to severe denial of service conditions. Prolonged downtime means organizations may suffer reputational damage and loss of customer trust. Resources could become depleted more rapidly due to the server handling incomplete or malformed requests. Organizations affected would incur costs related to recovery and mitigation of the exploit. In environments heavily reliant on React Server Components, these impacts are particularly profound, necessitating swift remediation.

REFERENCES

• https://vercel.com/kb/bulletin/security-bulletin-cve-2025-55184-and-cve-2025-55183#patched-versions
• https://www.facebook.com/security/advisories/cve-2025-55184
• https://react.dev/blog/2025/12/11/denial-of-service-and-source-code-exposure-in-react-server-components