We know that gmail is one of the most popular e-mail services, so it's no surprise that malware exists to try to influence the platform.
Google noticing the fact decided to help prevent this eventuality by adding support for Content Security Policy or in English Content Security to Gmail Policy (CSP).
CSP aims to stop malicious extensions and loading suspicious code that can compromise your email security. Google says it's done the same with Chrome extensions, and suggests installing the latest updates for your extensions from the Chrome Web Store to keep yourself safe.
Most of the popular extensions have already been updated to work with CSP, according to the company. It feature CSP είναι available only in the desktop version of the e-mail service at this time.