CVE-2026-49455

Medium

Description

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.

SeverityMedium
CVSS6.5
Exploit probability—
ProductWaku
PublishedSep 3, 2026
First seenSep 3, 2026

How to fix

Update
  • waku1.0.0-beta.1 or later

Affected products

ProductAffected versionsFixed in
wakunpmv < 1.0.0-beta.11.0.0-beta.1

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