React: Unauthenticated Remote Code Execution in React Server Components (CVE-2026-126187)
A critical remote code execution vulnerability in React Server Components packages allows unauthenticated attackers to execute code via crafted responses involving multiple typed arrays.
CVE search metadata
CVE search record: CVE-2026-126187. KEV: no. Product: react-server-dom-webpack, react-server-dom-parcel, react-server-dom-turbopack. Brief: React: Unauthenticated Remote Code Execution in React Server Components (CVE-2026-126187). Brief link: https://feed.craftedsignal.io/briefs/2026-11-react-rce/
Triage facts
Revision 1- Applicability
- react-server-dom-webpack, react-server-dom-parcel +1
- Evidence
- Unknown
- Severity
- Critical
- Sources
- 1 public source
- Freshness
- Revision 1Nov 11, 07:26 UTC
- Vulnerabilities
- 1 CVE
- Source quality
- B2Roughly even chance
CVE-2026-126187 is a critical remote code execution vulnerability affecting react-server-dom-webpack, react-server-dom-parcel, and react-server-dom-turbopack. The vulnerability occurs in rare cases where responses transport multiple typed arrays and an attacker-controlled value.
Scope
This affects applications using frameworks that support React Server Components. Applications not using a server, or not using a framework, bundler, or bundler plugin that supports React Server Components, are not affected.
Recommendation
Upgrade affected packages to versions 19.0.9, 19.1.10, 19.2.9, or 19.3.1.