Critical React Server Components RCE Hits Next.js and Related Ecosystem
A critical remote code execution vulnerability in React Server Components-related packages is affecting widely used parts of the React ecosystem, including deployments tied to Next.js, React Router, Expo, Redwood SDK, Waku, and @vitejs/plugin-rsc. The flaw allows an unauthenticated attacker to execute arbitrary code on a vulnerable system through an HTTP request. Affected versions include 19.0, 19.1.0, 19.1.1, and 19.2.0 of react-server-dom-webpack, react-server-dom-parcel, and react-server-dom-turbopack, while patched releases are 19.0.1, 19.1.2, and 19.2.1.
Authorities warned that exploitation is already active in Finland and that public exploit methods are available, increasing the likelihood of rapid opportunistic attacks against exposed applications. Officials said attackers may use the vulnerability not only for visible abuse such as cryptomining but also to establish persistent access, and urged organizations to patch immediately and assess internet-exposed systems for signs of compromise.
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3 events from the most recent confirmed update back to the earliest known activity.
Active exploitation of React RCE observed in Finland
Finnish authorities reported active exploitation in Finland of the critical React Server Components vulnerability. They warned attackers may use the flaw for visible activity such as cryptomining as well as to establish persistent access, and urged immediate patching and compromise assessment of exposed systems.
Public exploit methods emerge for React Server Components flaw
Public exploitation methods became available for the critical React Server Components vulnerability, lowering the barrier to abuse. The flaw impacts products identified by React such as Next.js, React Router, Expo, Redwood SDK, Waku, and @vitejs/plugin-rsc, along with potentially other implementations using the affected packages.
React fixes critical RCE in React Server Components packages
React released patched versions 19.0.1, 19.1.2, and 19.2.1 for the affected react-server-dom-webpack, react-server-dom-parcel, and react-server-dom-turbopack packages. The vulnerability affects versions 19.0, 19.1.0, 19.1.1, and 19.2.0 and can allow unauthenticated remote code execution via an HTTP request.
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Critical Unauthenticated RCE Vulnerabilities in React Server Components and Next.js
A critical unauthenticated remote code execution (RCE) vulnerability, tracked as CVE-2025-55182, has been discovered in React Server Components, affecting core React packages (`react-server-dom-webpack`, `react-server-dom-parcel`, and `react-server-dom-turbopack`) in versions 19.0, 19.1.0, 19.1.1, and 19.2.0. The flaw arises from unsafe deserialization of payloads sent to React Server Function endpoints, allowing attackers to execute arbitrary code on the server without authentication. This vulnerability also impacts frameworks and bundlers that integrate React Server Components, including Next.js (assigned CVE-2025-66478), Vite, Parcel, React Router, RedwoodSDK, and Waku. Even default configurations and newly generated Next.js applications are vulnerable, and exploitation requires only a crafted HTTP request, with no developer error or special setup needed. Immediate patching is strongly advised, as the vulnerability is rated CVSS 10.0 (critical) and has been shown to be highly reliable in exploitation tests. Patched versions are available for React (19.0.1, 19.1.2, 19.2.1) and Next.js (15.0.5, 15.1.9, 15.2.6, 15.3.6, 15.4.8, 15.5.7, 16.0.7), and users are urged to upgrade all affected packages and dependencies. Some hosting providers, such as Vercel, have implemented temporary platform-level mitigations, but these are not a substitute for patching. Security researchers estimate that up to 39% of cloud environments may contain vulnerable instances, underscoring the urgency of remediation across the React and Next.js ecosystem.
Mar 21, 2026
Denial-of-Service and Source Code Exposure Vulnerabilities in React Server Components
Security researchers have identified three new vulnerabilities in React Server Components (RSC) following the recent patch for the critical React2Shell exploit. These flaws include two high-severity Denial-of-Service (DoS) vulnerabilities (CVE-2025-55184 and CVE-2025-67779) and a medium-severity Source Code Exposure vulnerability (CVE-2025-55183). The DoS vulnerabilities allow attackers to send malicious HTTP requests to Server Function endpoints, triggering infinite loops that hang the server and exhaust CPU resources, effectively taking applications offline. The source code exposure flaw enables attackers to craft HTTP requests that can leak the source code of server functions, potentially exposing hardcoded secrets or sensitive logic, though runtime secrets remain protected. The affected packages are `react-server-dom-webpack`, `react-server-dom-parcel`, and `react-server-dom-turbopack`, impacting React versions 19.0.0 through 19.2.2 and frameworks such as Next.js, Waku, and React Router. Initial patches released for these vulnerabilities were incomplete, necessitating immediate upgrades to versions 19.0.3, 19.1.4, and 19.2.3 to ensure full protection. The vulnerabilities were discovered by security researchers during attempts to bypass previous mitigations, highlighting the importance of rapid patch adoption and ongoing scrutiny of critical code paths after major disclosures. Users are strongly advised to update affected packages and monitor official channels for further security updates.
Mar 21, 2026Denial-of-Service and Source Code Exposure Vulnerabilities in React Server Components
Multiple vulnerabilities have been identified in React Server Components (RSC), specifically CVE-2025-55183, CVE-2025-55184, and CVE-2025-67779, affecting several versions of `react-server-dom-webpack`, `react-server-dom-parcel`, and `react-server-dom-turbopack`. These vulnerabilities, discovered following the React2Shell incident, include a high-severity denial-of-service (DoS) flaw (CVE-2025-55184) caused by unsafe deserialization of structured input in the RSC Flight protocol, which can be exploited by sending specially crafted requests that trigger infinite loops or event-loop lockups on the server. The vulnerabilities also raise concerns about potential source code exposure and highlight the risk of residual flaws being discovered after major disclosures. The React Foundation has issued advisories and patches for affected versions, and the Canadian Centre for Cyber Security has urged administrators to update impacted libraries and frameworks, including popular tools such as Next.js, Vite RSC plugin, Parcel RSC plugin, React Router RSC preview, RedwoodSDK, and Waku. No public exploits are currently available, but the vulnerabilities have a higher-than-average likelihood of exploitation, emphasizing the importance of prompt remediation and ongoing vigilance for follow-on issues after initial vulnerability disclosures.
Mar 21, 2026