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CVE-2026-126187

React: Unauthenticated Remote Code Execution in React Server Components

publishedCWE-502

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.

Technical severity9.5 criticalCVSS 4.0 · CNA: GitHub_M
Published2026-11-10Source updated 2026-11-10
Collected2026-11-102 attributed sources

Fixes and workarounds

Fix

react-server-dom-parcel (npm): OSV reports a fixed version 19.0.9. Check the advisory for supported release branches.

Source: OSV GHSA-xqc2-xf4c-x3h3

Fix

react-server-dom-parcel (npm): OSV reports a fixed version 19.1.10. Check the advisory for supported release branches.

Source: OSV GHSA-xqc2-xf4c-x3h3

Fix

react-server-dom-parcel (npm): OSV reports a fixed version 19.2.9. Check the advisory for supported release branches.

Source: OSV GHSA-xqc2-xf4c-x3h3

Fix

react-server-dom-parcel (npm): OSV reports a fixed version 19.3.1. Check the advisory for supported release branches.

Source: OSV GHSA-xqc2-xf4c-x3h3

Fix

react-server-dom-turbopack (npm): OSV reports a fixed version 19.0.9. Check the advisory for supported release branches.

Source: OSV GHSA-xqc2-xf4c-x3h3

Fix

react-server-dom-turbopack (npm): OSV reports a fixed version 19.1.10. Check the advisory for supported release branches.

Source: OSV GHSA-xqc2-xf4c-x3h3

Fix

react-server-dom-turbopack (npm): OSV reports a fixed version 19.2.9. Check the advisory for supported release branches.

Source: OSV GHSA-xqc2-xf4c-x3h3

Fix

react-server-dom-turbopack (npm): OSV reports a fixed version 19.3.1. Check the advisory for supported release branches.

Source: OSV GHSA-xqc2-xf4c-x3h3

Fix

react-server-dom-webpack (npm): OSV reports a fixed version 19.0.9. Check the advisory for supported release branches.

Source: OSV GHSA-xqc2-xf4c-x3h3

Fix

react-server-dom-webpack (npm): OSV reports a fixed version 19.1.10. Check the advisory for supported release branches.

Source: OSV GHSA-xqc2-xf4c-x3h3

Fix

react-server-dom-webpack (npm): OSV reports a fixed version 19.2.9. Check the advisory for supported release branches.

Source: OSV GHSA-xqc2-xf4c-x3h3

Fix

react-server-dom-webpack (npm): OSV reports a fixed version 19.3.1. Check the advisory for supported release branches.

Source: OSV GHSA-xqc2-xf4c-x3h3

Affected products and versions

ProductVersionsAuthority
react
react 		>= 19.0.0, < 19.0.9 (affected)
>= 19.1.0, < 19.1.10 (affected)
>= 19.2.0, < 19.2.9 (affected)
>= 19.3.0, < 19.3.1 (affected) 		CNA: GitHub_M
react-server-dom-parcel

react-server-dom-parcel
npm 		≥ 19.0.0; < 19.0.9 (affected, semver); OSV events: introduced 19.0.0; fixed 19.0.9
Source events (semver) 
[
  {
    "introduced": "19.0.0"
  },
  {
    "fixed": "19.0.9"
  }
]

Other versions: unaffected 		OSV GHSA-xqc2-xf4c-x3h3
react-server-dom-parcel

react-server-dom-parcel
npm 		≥ 19.1.0; < 19.1.10 (affected, semver); OSV events: introduced 19.1.0; fixed 19.1.10
Source events (semver) 
[
  {
    "introduced": "19.1.0"
  },
  {
    "fixed": "19.1.10"
  }
]

Other versions: unaffected 		OSV GHSA-xqc2-xf4c-x3h3
react-server-dom-parcel

react-server-dom-parcel
npm 		≥ 19.2.0; < 19.2.9 (affected, semver); OSV events: introduced 19.2.0; fixed 19.2.9
Source events (semver) 
[
  {
    "introduced": "19.2.0"
  },
  {
    "fixed": "19.2.9"
  }
]

Other versions: unaffected 		OSV GHSA-xqc2-xf4c-x3h3
react-server-dom-parcel

react-server-dom-parcel
npm 		≥ 19.3.0; < 19.3.1 (affected, semver); OSV events: introduced 19.3.0; fixed 19.3.1
Source events (semver) 
[
  {
    "introduced": "19.3.0"
  },
  {
    "fixed": "19.3.1"
  }
]

Other versions: unaffected 		OSV GHSA-xqc2-xf4c-x3h3
react-server-dom-turbopack

react-server-dom-turbopack
npm 		≥ 19.0.0; < 19.0.9 (affected, semver); OSV events: introduced 19.0.0; fixed 19.0.9
Source events (semver) 
[
  {
    "introduced": "19.0.0"
  },
  {
    "fixed": "19.0.9"
  }
]

Other versions: unaffected 		OSV GHSA-xqc2-xf4c-x3h3
react-server-dom-turbopack

react-server-dom-turbopack
npm 		≥ 19.1.0; < 19.1.10 (affected, semver); OSV events: introduced 19.1.0; fixed 19.1.10
Source events (semver) 
[
  {
    "introduced": "19.1.0"
  },
  {
    "fixed": "19.1.10"
  }
]

Other versions: unaffected 		OSV GHSA-xqc2-xf4c-x3h3
react-server-dom-turbopack

react-server-dom-turbopack
npm 		≥ 19.2.0; < 19.2.9 (affected, semver); OSV events: introduced 19.2.0; fixed 19.2.9
Source events (semver) 
[
  {
    "introduced": "19.2.0"
  },
  {
    "fixed": "19.2.9"
  }
]

Other versions: unaffected 		OSV GHSA-xqc2-xf4c-x3h3
react-server-dom-turbopack

react-server-dom-turbopack
npm 		≥ 19.3.0; < 19.3.1 (affected, semver); OSV events: introduced 19.3.0; fixed 19.3.1
Source events (semver) 
[
  {
    "introduced": "19.3.0"
  },
  {
    "fixed": "19.3.1"
  }
]

Other versions: unaffected 		OSV GHSA-xqc2-xf4c-x3h3
react-server-dom-webpack

react-server-dom-webpack
npm 		≥ 19.0.0; < 19.0.9 (affected, semver); OSV events: introduced 19.0.0; fixed 19.0.9
Source events (semver) 
[
  {
    "introduced": "19.0.0"
  },
  {
    "fixed": "19.0.9"
  }
]

Other versions: unaffected 		OSV GHSA-xqc2-xf4c-x3h3
react-server-dom-webpack

react-server-dom-webpack
npm 		≥ 19.1.0; < 19.1.10 (affected, semver); OSV events: introduced 19.1.0; fixed 19.1.10
Source events (semver) 
[
  {
    "introduced": "19.1.0"
  },
  {
    "fixed": "19.1.10"
  }
]

Other versions: unaffected 		OSV GHSA-xqc2-xf4c-x3h3
react-server-dom-webpack

react-server-dom-webpack
npm 		≥ 19.2.0; < 19.2.9 (affected, semver); OSV events: introduced 19.2.0; fixed 19.2.9
Source events (semver) 
[
  {
    "introduced": "19.2.0"
  },
  {
    "fixed": "19.2.9"
  }
]

Other versions: unaffected 		OSV GHSA-xqc2-xf4c-x3h3
react-server-dom-webpack

react-server-dom-webpack
npm 		≥ 19.3.0; < 19.3.1 (affected, semver); OSV events: introduced 19.3.0; fixed 19.3.1
Source events (semver) 
[
  {
    "introduced": "19.3.0"
  },
  {
    "fixed": "19.3.1"
  }
]

Other versions: unaffected 		OSV GHSA-xqc2-xf4c-x3h3

Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.

CVSS assessments

Version / scoreVectorAuthority
4.0 / 9.5
critical		 CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:NCNA: GitHub_M

Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

References

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