UBUNTU-CVE-2026-126187: Medium severity ubuntu/react vulnerability
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.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
react-server-dom-webpackto a version that resolves this vulnerability.Fixed in 19.0.9 - Upgrade
Upgrade
react-server-dom-webpackto a version that resolves this vulnerability.Fixed in 19.1.10 - Upgrade
Upgrade
react-server-dom-webpackto a version that resolves this vulnerability.Fixed in 19.2.9 - Upgrade
Upgrade
react-server-dom-webpackto a version that resolves this vulnerability.Fixed in 19.3.1 - Upgrade
Upgrade
react-server-dom-parcelto a version that resolves this vulnerability.Fixed in 19.0.9 - Upgrade
Upgrade
react-server-dom-parcelto a version that resolves this vulnerability.Fixed in 19.1.10 - Upgrade
Upgrade
react-server-dom-parcelto a version that resolves this vulnerability.Fixed in 19.2.9 - Upgrade
Upgrade
react-server-dom-parcelto a version that resolves this vulnerability.Fixed in 19.3.1 - Upgrade
Upgrade
react-server-dom-turbopackto a version that resolves this vulnerability.Fixed in 19.0.9 - Upgrade
Upgrade
react-server-dom-turbopackto a version that resolves this vulnerability.Fixed in 19.1.10 - Upgrade
Upgrade
react-server-dom-turbopackto a version that resolves this vulnerability.Fixed in 19.2.9 - Upgrade
Upgrade
react-server-dom-turbopackto a version that resolves this vulnerability.Fixed in 19.3.1
Event History
Frequently Asked Questions
Which applications are exposed to this issue?
Exposure is limited to applications using React Server Components through a supporting framework, bundler, or bundler plugin, and using one of the affected react-server-dom-webpack, react-server-dom-parcel, or react-server-dom-turbopack packages. React applications that do not use a server, or do not use React Server Components support, are not affected.
What must an attacker be able to do to exploit it?
The issue is unauthenticated, so no login is required. Exploitation requires crafting payloads for a vulnerable React Server Components-enabled application in the rare situation where responses transport multiple typed arrays together with an attacker-controlled value.
Which versions contain fixes?
The issue is fixed in React versions 19.0.9, 19.1.10, 19.2.9, and 19.3.1.