CVE-2026-42211: CWE-502: Deserialization of Untrusted Data in remix-run react-router
React Router is a router for React. In versions 7.0.0 through 7.14.1, when using Framework Mode, a combination of steps could potentially allow unauthorized remote code execution (RCE) through external requests. This attack requires the application code to have an existing prototype pollution vulnerability, which can then be leveraged in a 2-step attack where the second step triggers unauthorized RCE on the remote server. This does not impact applications using Declarative Mode (`<BrowserRouter>`) or Data Mode (`createBrowserRouter/<RouterProvider>`). This is patched in version 7.14.2.
AI Analysis
Technical Summary
React Router, a routing library for React, has a deserialization vulnerability (CWE-502) in Framework Mode in versions 7.0.0 to 7.14.1. An attacker can exploit this by leveraging an existing prototype pollution vulnerability in the application to perform a two-step attack culminating in remote code execution on the server. This vulnerability does not affect applications using Declarative Mode (<BrowserRouter>) or Data Mode (createBrowserRouter/<RouterProvider>). The vulnerability is patched in version 7.14.2.
Potential Impact
Successful exploitation allows an attacker to execute arbitrary code remotely on the server running the vulnerable react-router Framework Mode, leading to full compromise of confidentiality, integrity, and availability of the affected system. The attack requires a prerequisite prototype pollution vulnerability in the application code, making it a chained exploit scenario.
Mitigation Recommendations
Upgrade react-router to version 7.14.2 or later, where this vulnerability is patched. Applications using Declarative Mode or Data Mode are not affected by this issue. Since no official vendor advisory text is provided, patch status is confirmed by the version information in the description. Check the vendor's official release notes for confirmation and apply the update promptly.
CVE-2026-42211: CWE-502: Deserialization of Untrusted Data in remix-run react-router
Description
React Router is a router for React. In versions 7.0.0 through 7.14.1, when using Framework Mode, a combination of steps could potentially allow unauthorized remote code execution (RCE) through external requests. This attack requires the application code to have an existing prototype pollution vulnerability, which can then be leveraged in a 2-step attack where the second step triggers unauthorized RCE on the remote server. This does not impact applications using Declarative Mode (`<BrowserRouter>`) or Data Mode (`createBrowserRouter/<RouterProvider>`). This is patched in version 7.14.2.
CVSS v3.1
Score 8.1high
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
React Router, a routing library for React, has a deserialization vulnerability (CWE-502) in Framework Mode in versions 7.0.0 to 7.14.1. An attacker can exploit this by leveraging an existing prototype pollution vulnerability in the application to perform a two-step attack culminating in remote code execution on the server. This vulnerability does not affect applications using Declarative Mode (<BrowserRouter>) or Data Mode (createBrowserRouter/<RouterProvider>). The vulnerability is patched in version 7.14.2.
Potential Impact
Successful exploitation allows an attacker to execute arbitrary code remotely on the server running the vulnerable react-router Framework Mode, leading to full compromise of confidentiality, integrity, and availability of the affected system. The attack requires a prerequisite prototype pollution vulnerability in the application code, making it a chained exploit scenario.
Mitigation Recommendations
Upgrade react-router to version 7.14.2 or later, where this vulnerability is patched. Applications using Declarative Mode or Data Mode are not affected by this issue. Since no official vendor advisory text is provided, patch status is confirmed by the version information in the description. Check the vendor's official release notes for confirmation and apply the update promptly.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-04-25T05:04:37.028Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a1f3494e29bf47b50fa2521
Added to database: 6/2/2026, 7:52:52 PM
Last enriched: 6/2/2026, 8:03:54 PM
Last updated: 6/3/2026, 5:00:17 AM
Views: 7
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