Critical Security Vulnerability in React Server Components
Key Points
- Unauthenticated RCE in React Server Components (CVE-2025-55182)
- CVSS 10.0 — upgrade react-server-dom-* to fixed versions immediately
- Fixed in react-server-dom-* 19.0.1, 19.1.2, 19.2.1
Summary
There is an unauthenticated remote code execution (RCE) vulnerability in React Server Components disclosed as CVE-2025-55182 (CVSS 10.0). The flaw affects how React decodes payloads sent to React Server Function endpoints and allows an attacker to craft a malicious request that may achieve RCE on servers exposing Server Function endpoints. The issue was reported on 2025-11-29 and publicly disclosed on 2025-12-03 after fixes were published.
Key Points
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Affected packages and vulnerable versions
- react-server-dom-webpack, react-server-dom-parcel, react-server-dom-turbopack in versions 19.0, 19.1.0, 19.1.1, and 19.2.0 are vulnerable.
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Fixed versions (upgrade immediately)
- Upgrade to any fixed release in your release line: 19.0.1, 19.1.2, or 19.2.1 depending on the series you use.
- Example (pick the fixed version that matches your minor series):
- npm install react-server-dom-webpack@19.0.1 react-server-dom-parcel@19.0.1 react-server-dom-turbopack@19.0.1
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Frameworks and bundlers impacted
- Some frameworks/bundlers that depend on or include the vulnerable packages are affected (notably Next.js, react-router RSC APIs, waku, @parcel/rsc, @vitejs/plugin-rsc, rwsdk). Upgrade those projects per their published advisories.
- Next.js users: upgrade to the patched release for your release line as documented by the Next.js team.
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Mitigations and scope
- If your app does not use a server (no Server Functions) or does not use a framework/bundler that supports React Server Components, you are not affected.
- Hosting-provider mitigations were applied by some providers but should not be relied on; update dependencies immediately.
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Additional notes
- Follow-up advisories added other CVEs (DoS and source-code exposure) in later updates; check the React security blog for the full, updated guidance and timelines.
Recommended Action Plan (for engineers)
- Audit: identify any installs of react-server-dom-webpack, react-server-dom-parcel, or react-server-dom-turbopack in your projects, monorepos, and transitive deps.
- Upgrade: update the vulnerable packages to the corresponding fixed versions (19.0.1, 19.1.2, or 19.2.1) and update affected frameworks/bundlers per vendor guidance.
- Test & Deploy: run tests, validate Server Function endpoints, and deploy the patched versions quickly.
- Monitor: review your hosting provider notices and the React security blog for further technical details released after the fix rollout.