# CVE-2026-42211: React Router's vendored turbo-stream v2 allows arbitrary constructor invocation via TYPE_ERROR deserialization leading to Unauth RCE > CVE-2026-42211: React Router's vendored turbo-stream v2 allows arbitrary constructor invocation via TYPE_ERROR deserialization leading to Unauth RCE. CVSS 8.1 (CVSS 3.1). Canonical: https://rewindex.com/cve/CVE-2026-42211 Last updated: 2026-07-21T19:10:00Z - Published: 2026-06-02 18:18 UTC · Updated: 2026-07-21 19:10 UTC · Assigner: GitHub\_M - CVSS: 8.1 (CVSS 3.1) · Severity: High · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - EPSS: 0.42%, 36th percentile (scored 2026-10-25) - CISA KEV: no - CWE: CWE-502 ## 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 (\`\\`) or Data Mode (\`createBrowserRouter/\\`). This is patched in version 7.14.2. ## Affected vendors and products - remix-run: react-router ## Tracked companies - [Jira](https://rewindex.com/company/jira.md) ## References - [CVE record on cve.org](https://www.cve.org/CVERecord?id=CVE-2026-42211) - [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2026-42211) - [https://github.com/remix-run/react-router/security/advisories/GHSA-49rj-9fvp-4h2h](https://github.com/remix-run/react-router/security/advisories/GHSA-49rj-9fvp-4h2h) --- _Sources: CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (https://www.cve.org/) This product uses data from the NVD API but is not endorsed or certified by the NVD. (https://nvd.nist.gov/) Known Exploited Vulnerabilities catalog from CISA. (https://www.cisa.gov/known-exploited-vulnerabilities-catalog) EPSS scores from FIRST (Exploit Prediction Scoring System). (https://www.first.org/epss/)_ --- Canonical: https://rewindex.com/cve/CVE-2026-42211 · Markdown: https://rewindex.com/cve/CVE-2026-42211.md · JSON: https://rewindex.com/api/v1/cves/CVE-2026-42211 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T02:16:58.011Z