Waku: Cross-Origin CSRF on RSC Server Action Dispatch (CVE-2026-49455) | HOL Guard CVE

Medium · CVSS 6.5CVE-2026-49455GHSA-75W3-GMQX-993Q

Waku: Cross-Origin CSRF on RSC Server Action Dispatch

Answer in brief

CVE-2026-49455 records a Medium severity (CVSS 6.5) vulnerability in Waku: Cross-Origin CSRF on RSC Server Action Dispatch. The current sources do not mark it as known exploited. The current feed maps wakujs/waku (generic), waku (npm). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 3, 2026Updated Sep 9, 2026Source checked Sep 17, 2026First seen by HOL Jul 8, 2026Material review Sep 9, 2026

Upstream Advisory

Key facts

Risk: Medium · CVSS 6.5
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

CVSS is 6.5. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps wakujs/waku (generic), waku (npm). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
wakujs/wakugeneric	< 1.0.0-beta.1	Not reported
wakunpm	<=1.0.0-beta.0	1.0.0-beta.1

Recommended response

Check inventory. Check lockfiles and deployed manifests for wakujs/waku, waku.
Review the reported fix. Update waku to 1.0.0-beta.1 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 3, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 9, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Jul 8, 2026

Sources and claim methodology

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.