vulnerability / NVI-00017738 / Revision 1
Waku: Cross-Origin CSRF on RSC Server Action Dispatch
GitHub lists this reviewed advisory for waku. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.
This report has not inspected your inventory, configuration, deployed build, reachability or evidence. A catalog listing and a severity score do not establish exposure or compromise.
01 / Meaning
Why it matters
Published affected context helps an owner decide what evidence to gather. This report has not examined your application.
6.5 medium
GitHub source severity; exploitability and local consequence require separate evidence.
As of · GitHub Advisory Database
02 / Applicability
The affected context
Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.
waku
source listed<= 1.0.0-beta.0
## Summary 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. A working proof-of-concept demonstrates the vulnerability against waku 1.0.0-beta.0 dev server: a cross-origin POST with `Content-Type: text/plain` invokes a registered `'use server'` action and returns HTTP 200 with an RSC stream response. The same defect affects the progressive-enhancement (no-JavaScript) server action path: a cross-origin HTML form auto-submitting `multipart/form-data` reaches the dispatch through a second unguarded branch of the request handler, dynamically confirmed on 2026-05-17. Both branches were confirmed exploitable from opaque-origin contexts (sandboxed iframes, `file://` navigation, browser extension pages), which send `Origin: null` — a value no Origin guard exists t
03 / Response
What to do next
- investigate
Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. GitHub Advisory Database
A fixed release is not deployment evidence.
Check current vendor support and compatibility. After making a change, verify the deployed build and relevant runtime conditions. Keep the evidence, owner and time. An updated lockfile alone does not prove what is running.
04 / Limits
What this report cannot establish
- Customer inventory, deployment, reachability and exploitation have not been inspected.
05 / Provenance
Sources you can inspect
Each assertion retains its source. Mirrored records may repeat one underlying publisher; additional links are not independent corroboration.
- GHSA-75w3-gmqx-993q ↗
GitHub Advisory Database · vendor advisory
Observed . GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.
Public revision history
Only published revisions appear here. Routine fetches do not create a material-change event.
- Revision 1 ·
First indexed by Null; source disclosure date is shown separately.