medium6.5
CVE-2026-49455
Waku: Cross-Origin CSRF on RSC Server Action Dispatch
Impact
Waku is the minimal React framework. Prior to version 1.0.0-beta.1, Waku's RSC request dispatcher invokes server actions without validating the request's Origin (or Sec-Fetch-Site) header. A cross-origin web attacker can therefore cause a victim browser to issue an authenticated POST to a registered server action endpoint using a CORS-safelisted content type (text/plain), which does not trigger a preflight. Any state-mutating server action that the application exposes via 'use server' can be invoked with the victim's cookies attached. This issue has been patched in version 1.0.0-beta.1.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| npm | waku | <= 1.0.0-beta.0 | 1.0.0-beta.1 |