GitLab: Mailgun misconfiguration leads to email snooping and postmaster@-access on email.mg.gitlab.com

Hi, Previously a blog post went out about Uber's Sendgrid issues: http://blog.pentestnepal.tech/post/149985438982/reading-ubers-internal-emails-uber-bug-bounty Also, a report from @uranium238 went out due to a similar issue with Slack that I know uses Mailgun: https://hackerone.com/reports/163938...