CVE-2026-49455
Waku: Cross-Origin CSRF on RSC Server Action Dispatch
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.
INFO
Published Date :
Sept. 3, 2026, 7:17 p.m.
Last Modified :
Sept. 3, 2026, 7:17 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-49455
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Update Waku to version 1.0.0-beta.1 or later.
- Validate the request's Origin or Sec-Fetch-Site header.
- Ensure server actions are protected against cross-origin calls.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-49455.
| URL | Resource |
|---|---|
| https://github.com/wakujs/waku/releases/tag/v1.0.0-beta.1 | |
| https://github.com/wakujs/waku/security/advisories/GHSA-75w3-gmqx-993q |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-49455 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-49455
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-49455 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-49455 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by [email protected]
Sep. 03, 2026
Action Type Old Value New Value Added 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. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N Added CWE CWE-352 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/49xxx/CVE-2026-49455.json">CVE-2026-49455</a> Added Reference https://github.com/wakujs/waku/releases/tag/v1.0.0-beta.1 Added Reference https://github.com/wakujs/waku/security/advisories/GHSA-75w3-gmqx-993q -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Sep. 03, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-49455', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-09-03T18:32:58.949158Z'}