React Router: Cross-site Scripting is Possible due to Missing RSCErrorHandler Protocol Validation (Incomplete fix for CVE-2026-53667)
13Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 6.9epss 0.4%
exploitation probability
0.4%top 72% of all CVEs
observed exploitation
nono source reports it
React Router is a router for React. In versions 7.11.0 through 7.17.0, the RSCErrorHandler is missing protocol validation, allowing for redirects from untrusted sources. This issue is a follow up to CVE-2026-53667, and only affects consuming applications if they are using the unstable RSC APIs. This issue has been fixed in version 7.18.0.
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:L/A:N
Affected products
remix-run · react-routerReferences
https://github.com/remix-run/react-router/blob/main/CHANGELOG.md#v7180https://github.com/remix-run/react-router/commit/ce596e823f0d7b883a433af1d5a839a8b9fe0242https://github.com/remix-run/react-router/pull/15177https://github.com/remix-run/react-router/releases/tag/react-router@7.18.0https://github.com/remix-run/react-router/security/advisories/GHSA-h8fp-f39c-q6mh