React Router: Arbitrary Constructor Injection via deserializeErrors() in React Router SSR Hydration

Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

Severity and exploitation

• CISA KEV Not listed.
• EPSS 0.0042, the 36th percentile, on 13 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

1. 22 Jul 2026, 16:22 UTC Published by the maintainers as a GitHub repository advisory

Sources

• GitHub Advisory Database: GHSA-337j-9hxr-rhxg
• OSV: GHSA-337j-9hxr-rhxg
• github.com/remix-run/react-router/security/advisories/GHSA-337j-9hxr-rhxg
• github.com/remix-run/react-router/pull/15175
• github.com/remix-run/react-router/commit/9d22943fd46c8ae4b08236425fa3549e10e9ad1a
• github.com/remix-run/react-router
• github.com/remix-run/react-router/blob/main/CHANGELOG.md#v7180
• github.com/remix-run/react-router/releases/tag/[email protected]

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.