CVE-2026-49455 — MEDIUM (6.5)

Vulnerability 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.

CVSS Score

6.5

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

REQUIRED

Scope

UNCHANGED

Confidentiality

NONE

Integrity

HIGH

Availability

NONE

Related Weaknesses (CWE)

CWE-352

References

FAQ

What is CVE-2026-49455?

CVE-2026-49455 is a vulnerability with a CVSS score of 6.5 (MEDIUM). 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-ori...

How severe is CVE-2026-49455?

CVE-2026-49455 has been rated MEDIUM with a CVSS base score of 6.5/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-49455?

Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.