CVE-2026-63407 Grav API Plugin: CORS 'Access-Control-Allow-Origin: *' on Authenticated API Responses
An attacker can bypass CORS restrictions to read and modify authenticated API data using a stolen token, affecting Grav CMS users.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-63407?
CVE-2026-63407 is a high-severity vulnerability in getgrav grav-plugin-api, published on 19 Aug 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
Grav API Plugin is a RESTful API for Grav CMS that provides full headless access to your site's content. Prior to 1.0.0-rc.16, the Grav API plugin CorsMiddleware returns Access-Control-Allow-Origin: * and permissive OPTIONS responses for authenticated /api/v1 endpoints. JavaScript from any origin can submit an attacker-obtained JWT through the Authorization or X-API-Token header, read the authenticated response, and perform write operations with the token owner's privileges, enabling data exfiltration and account modification. This issue is fixed in version 1.0.0-rc.16.
Weakness: CWE-942
Which versions are affected by CVE-2026-63407?
How do I fix CVE-2026-63407?
No fix has been published for CVE-2026-63407 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-63407 being exploited?
There is no known exploitation of CVE-2026-63407 in the wild and no public exploit code.