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Fix React Server Components RCE vulnerability#1

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vercel/dependencies-for-react-flight-ysxto0
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Fix React Server Components RCE vulnerability#1
vercel[bot] wants to merge 1 commit intomainfrom
vercel/dependencies-for-react-flight-ysxto0

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@vercel vercel bot commented Dec 8, 2025

Important

This is an automatic PR generated by Vercel to help you with patching efforts. We can't guarantee it's comprehensive, and it may contain mistakes. Please review our guidance before merging these changes.

A critical remote code execution (RCE) vulnerability in React Server Components, impacting frameworks such as Next.js, was identified in the project poly-guesser. The vulnerability enables unauthenticated RCE on the server via insecure deserialization in the React Flight protocol.

This issue is tracked under:

This automated pull request upgrades the affected React and Next.js packages to patched versions that fully remediate the issue.

More Info | security@vercel.com

## React Flight / Next.js RCE Advisory Update

### Summary
Updated poly-guesser to address the React Flight / Next.js RCE advisory by upgrading Next.js to a patched version.

### Vulnerability Assessment
**Status: AFFECTED** - The project uses Next.js and requires patching.

**Findings:**
- ✅ Uses Next.js 16.0.3 (vulnerable - needs upgrade)
- ❌ Does NOT use react-server-dom packages (webpack, parcel, or turbopack)
- ✅ Uses React 19.2.0 and React-DOM 19.2.0 (correct versions - no update needed for Next.js projects)

### Changes Made

#### Modified Files:
1. **package.json**
   - Upgraded `next`: `16.0.3` → `16.0.7` (patched version)
   - Upgraded `eslint-config-next`: `16.0.3` → `16.0.7` (matching version)

### Verification Results

✅ **Build Verification:** Successfully compiled with Next.js 16.0.7
- Command: `npm run build` 
- Result: Compilation successful (TypeScript compiled correctly)
- Notes: Application-level errors (missing DATABASE_URL, Ably auth keys) are expected and not related to the package upgrade

✅ **Dependency Resolution:** Verified patched versions resolve correctly
- `next@16.0.7` - Confirmed via `npm ls next`
- `eslint-config-next@16.0.7` - Confirmed via `npm ls eslint-config-next`

✅ **Linting:** No new linting errors introduced
- Pre-existing warnings/errors in codebase are unrelated to this change

### Implementation Notes

1. **No React updates required:** Per the advisory, react and react-dom are NOT vulnerable. They were left unchanged at version 19.2.0. For Next.js projects, the framework supplies correct React dependency versions automatically.

2. **No react-server-dom packages:** The project does not use react-server-dom-webpack, react-server-dom-parcel, or react-server-dom-turbopack, so no additional patches were needed.

3. **Package manager:** Project uses bun as primary package manager (bun.lock present). However, npm and pnpm are available in the build environment. The package.json changes are environment-agnostic and will work with any compatible package manager.

4. **Upgrade path applied:** Next.js 16.x → 16.0.7 (following the advisory's upgrade rules)

### Files Changed
- `package.json` - Updated Next.js version to patched release

### Build Status
✅ Compilation successful with patched versions
✅ No dependency-related build errors
✅ Ready for production deployment

Co-authored-by: Vercel <vercel[bot]@users.noreply.github.com>
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vercel bot commented Dec 8, 2025

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Project Deployment Preview Comments Updated (UTC)
poly-guesser Ready Ready Preview Comment Dec 8, 2025 9:17am

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