CVE-2026-63408 Grav API Plugin: JWT Access Token Accepted via `?token=` URL Query Parameter
Attackers can steal JWT tokens from logs or history because the Grav API plugin accepts them via URL query parameters, allowing unauthorized API access.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-63408?
CVE-2026-63408 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, with no action from the victim.
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 JwtAuthenticator::extractBearerToken() accepts a JWT from the token URL query parameter on every /api/v1 route, including state-changing endpoints. Request URLs consequently expose valid access tokens through Apache, proxy, and CDN logs, browser history, and Referer headers, allowing a party with access to those records to reuse the token with the owner's API privileges. This issue is fixed in version 1.0.0-rc.16.
Weakness: CWE-598
Which versions are affected by CVE-2026-63408?
How do I fix CVE-2026-63408?
No fix has been published for CVE-2026-63408 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-63408 being exploited?
There is no known exploitation of CVE-2026-63408 in the wild and no public exploit code.