Security vulnerability in Chrome's JSONView extension?

I've used daily the JSONView Chrome extension (previously available in https://chrome.google.com/webstore/detail/jsonview/chklaanhfefbnpoihckbnefhakgolnmc?hl=en) for viewing JSON.

Just now I noticed that it has been automatically disabled from my browser. Visiting `chrome://extensions/` states "This extension contains a serious security vulnerability". And also, it's no longer available in the Chrome Web Store (see link above).

Any idea, what's the vulnerability? I tried to google, but found no info about this...