Here is the guide about 'How to send Pull Request to the Application Security Team liferay-appsec': https://liferay.atlassian.net/wiki/spaces/ENGAPPSECURITY/pages/1510735976/How+to+send+Pull+Request+to+the+Application+Security+Team+liferay-appsec
Here is a template you should use when you send a PR to the liferay-appsec' user: https://liferay.atlassian.net/wiki/spaces/ENGAPPSECURITY/pages/2289861613/Pull+request+template
Here is the introduction of Application Security Team: https://liferay.atlassian.net/wiki/spaces/ENGAPPSECURITY/overview?homepageId=1296042626