CRITICALCVSS v4 9.5Vulnerability

CVE-2026-126187

### 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.

Properties

Severity
critical
Summary
React: Unauthenticated Remote Code Execution in React Server Components
Nvd fetched at
2026-11-10T23:33:48.924589+00:00
Cvss severity
CRITICAL
Cvss score
9.5
Retrieved at
2026-11-10T23:34:27+00:00
Ghsa published
2026-11-10T22:44:12Z
Source url
https://github.com/advisories/GHSA-xqc2-xf4c-x3h3
Ghsa updated
2026-11-10T22:44:13Z
Ghsa id
GHSA-xqc2-xf4c-x3h3
Last source
GitHub Advisory Database
Score
9.5
Cvss version
4.0
Cve id
CVE-2026-126187
Cvss vector
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
First seen by Signal
2026-11-10T23:31:41+00:00
Is ghsa only
false
Vector
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Published at
2026-11-10T23:17:20.687
Last modified
2026-11-10T23:17:20.687

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CVE-2026-126187 (CVSS v4 9.5) — Ninja Signal Threat Intelligence | Ninja Signal