CVE-2026-53666

CVE-2026-53666 affects React Router versions 6.4.0 through 7.17.0 where attacker-supplied input could overwrite parts of errors captured during SSR, enabling arbitrary constructor execution on the client and triggering outbound network requests. This requires specific, unlikely application-layer ...

GHSA-337J-9HXR-RHXG React Router: Arbitrary Constructor Injection via deserializeErrors() in React Router SSR Hydration

If application code allows attacker supplied input to overwrite certain aspects of errors caught by the SSR process, then it was possible for attacker to trigger unexpected constructor execution on the client which would trigger outbound network traffic. This is only possible with very specific a...