CVE-2026-126187: React: Unauthenticated Remote Code Execution in React Server Components

Published Nov 10, 2026
·
Updated

Impact

Crafted payloads targeting frameworks supporting React Server Components can lead to remote code execution. This only affects extremely rare cases where responses transport multiple typed arrays and an attacker-controlled value.

Updating immediately is recommended.

The vulnerability exists in versions 19.0.0 through 19.0.8, 19.1.0 through 19.1.9, 19.2.0 through 19.2.8 and 19.3.0 of:

- react-server-dom-webpack - react-server-dom-parcel - react-server-dom-turbopack

Patches

Fixes were back ported to versions 19.0.09, 19.1.10, 19.2.9, and 19.3.1.

If applications are using any of the above packages please upgrade to any of the fixed versions immediately.

If an app’s React code does not use a server, the app is not affected by this vulnerability. If an app does not use a framework, bundler, or bundler plugin that supports React Server Components, the app is not affected by this vulnerability.

Other sources

React is a JavaScript library for building user interfaces. From 19.0.0 until 19.0.9, 19.1.10, 19.2.9, and 19.3.1, the react-server-dom-webpack, react-server-dom-parcel, and react-server-dom-turbopack packages are vulnerable to unauthenticated remote code execution through crafted payloads targeting frameworks that support React Server Components. The vulnerability only affects extremely rare cases where responses transport multiple typed arrays and an attacker-controlled value. Applications whose React code does not use a server are not affected. Applications that do not use a framework, bundler, or bundler plugin that supports React Server Components are not affected. This issue is fixed in versions 19.0.9, 19.1.10, 19.2.9, and 19.3.1.

— MITRE

Affected Software

12 affected componentsFixes available
npm/react-server-dom-webpack>=19.3.0<19.3.1
19.3.1
npm/react-server-dom-webpack>=19.2.0<19.2.9
19.2.9
npm/react-server-dom-webpack>=19.1.0<19.1.10
19.1.10
npm/react-server-dom-webpack>=19.0.0<19.0.9
19.0.9
npm/react-server-dom-turbopack>=19.3.0<19.3.1
19.3.1
npm/react-server-dom-turbopack>=19.2.0<19.2.9
19.2.9
npm/react-server-dom-turbopack>=19.1.0<19.1.10
19.1.10
npm/react-server-dom-turbopack>=19.0.0<19.0.9
19.0.9
npm/react-server-dom-parcel>=19.3.0<19.3.1
19.3.1
npm/react-server-dom-parcel>=19.2.0<19.2.9
19.2.9
npm/react-server-dom-parcel>=19.1.0<19.1.10
19.1.10
npm/react-server-dom-parcel>=19.0.0<19.0.9
19.0.9

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade npm/react-server-dom-webpack to a version that resolves this vulnerability.

    Fixed in 19.3.1
  2. Upgrade

    Upgrade npm/react-server-dom-webpack to a version that resolves this vulnerability.

    Fixed in 19.2.9
  3. Upgrade

    Upgrade npm/react-server-dom-webpack to a version that resolves this vulnerability.

    Fixed in 19.1.10
  4. Upgrade

    Upgrade npm/react-server-dom-webpack to a version that resolves this vulnerability.

    Fixed in 19.0.9
  5. Upgrade

    Upgrade npm/react-server-dom-turbopack to a version that resolves this vulnerability.

    Fixed in 19.3.1
  6. Upgrade

    Upgrade npm/react-server-dom-turbopack to a version that resolves this vulnerability.

    Fixed in 19.2.9
  7. Upgrade

    Upgrade npm/react-server-dom-turbopack to a version that resolves this vulnerability.

    Fixed in 19.1.10
  8. Upgrade

    Upgrade npm/react-server-dom-turbopack to a version that resolves this vulnerability.

    Fixed in 19.0.9
  9. Upgrade

    Upgrade npm/react-server-dom-parcel to a version that resolves this vulnerability.

    Fixed in 19.3.1
  10. Upgrade

    Upgrade npm/react-server-dom-parcel to a version that resolves this vulnerability.

    Fixed in 19.2.9
  11. Upgrade

    Upgrade npm/react-server-dom-parcel to a version that resolves this vulnerability.

    Fixed in 19.1.10
  12. Upgrade

    Upgrade npm/react-server-dom-parcel to a version that resolves this vulnerability.

    Fixed in 19.0.9
  13. Upgrade

    Upgrade react-server-dom-parcel, react-server-dom-turbopack, react-server-dom-webpack to a version that resolves this vulnerability.

    Fixed in 19.0.9
  14. Upgrade

    Upgrade react-server-dom-parcel, react-server-dom-turbopack, react-server-dom-webpack to a version that resolves this vulnerability.

    Fixed in 19.1.10
  15. Upgrade

    Upgrade react-server-dom-parcel, react-server-dom-turbopack, react-server-dom-webpack to a version that resolves this vulnerability.

    Fixed in 19.2.9
  16. Upgrade

    Upgrade react-server-dom-parcel, react-server-dom-turbopack, react-server-dom-webpack to a version that resolves this vulnerability.

    Fixed in 19.3.1

Event History

Nov 10, 2026
CVE Published
via MITRE·10:33 PM
Data Sourced
via MITRE·10:33 PM
DescriptionWeakness
Advisory Published
via GitHub·10:44 PM
Data Sourced
via GitHub·10:44 PM
DescriptionWeaknessAffected Software
Data Sourced
via OSV·10:44 PM
DescriptionSeverityWeaknessAffected Software

Company

Resources

Contact

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