TanStack Router: Unauthenticated reflected XSS in TanStack Start server-function responses
High-risk advisory
CVE-2026-102989
Summary
TanStack Router: Unauthenticated reflected XSS in TanStack Start server-function responses
Why it matters
GitHub has published a reviewed security advisory for @tanstack/start-server-core. Prioritize it with other application dependency updates, especially because EPSS places it in the 43% percentile.
Operator check
Check whether @tanstack/start-server-core is present in application dependency manifests, lockfiles, or build images. Review the GitHub advisory and upgrade to a patched version where available. EPSS probability: 0.5%; percentile: 43%.
Sources
PatchBrief uses public sources. It does not scan environments, verify exposure, or replace vendor guidance.