RedwoodSDK is a server-first React framework. From 1.0.0-beta.50 to 1.0.5, erver functions exported from "use server" files could be invoked via GET requests, bypassing their intended HTTP method. In cookie-authenticated applications, this allowed cross-site GET navigations to trigger state-changing functions, because browsers send SameSite=Lax cookies on top-level GET requests. This affected all server functions -- both serverAction() handlers and bare exported functions in "use server" files. This vulnerability is fixed in 1.0.6.

Affected: npm: rwsdk

**Summary**

Server functions exported from `"use server"` files could be invoked via GET requests, bypassing their intended HTTP method. In cookie-authenticated applications, this allowed cross-site GET navigations to trigger state-changing functions, because browsers send `SameSite=Lax` cookies on top-level GET requests.

This affected all server functions -- both `serverAction()` handlers and bare exported functions in `"use server"` files.

**Impact**

An attacker could construct a URL containing a known action ID and JSON-encoded arguments. When a victim with an active session visited or was redirected to this URL, the function executed with the victim's credentials. This affected any server function that performs state-changing operations (writes, deletes, mutations) in applications using cookie-based authentication.

**Remediation**

Update to rwsdk `1.0.6`. No application code changes are required.

The fix enforces the declared HTTP method at dispatch time. GET requests to server functions that require POST now return `405 Method Not Allowed`.