hono: CORS Middleware reflects any Origin with credentials when `origin` defaults to the wildcard
- When
- Where
- Global (internet)
- Category
- cyber_advisory · npm
### Summary With `credentials: true` and no explicit `origin` (the default wildcard), the CORS Middleware reflects the request's `Origin` and sends `Access-Control-Allow-Credentials: true`. Any site can then make credentialed cross-origin requests and read the responses, exposing cookie-authenticated endpoints to arbitrary origins. ### Details The spec forbids `Access-Control-Allow-Origin: *` with credentials and browsers reject it, so this configuration used to fail closed. In affected versions the middleware reflects the request `Origin` instead, so it now succeeds for every origin, including `null`. The preflight also echoes the requested headers back, approving non-simple credentialed requests too. This issue arises when an application enables `credentials: true` and leaves `origin` unset or set to the wildcard. ### Impact Any third-party page a logged-in user visits can read the application's cookie-authenticated endpoints and perform credentialed state-changing requests. This affects applications that enable credentialed CORS without restricting `origin`.
Sources
- GitHub Advisory Database ↗ · first seen 2026-06-16 14:15 UTC
Defaxon links out to the original reporting and never republishes article text.
Correlated events
Computed by the Defaxon correlation engine — linked by shared actors, co-location, and temporal proximity. Scored hypotheses, never causal claims.