The JetBrains Vim plugin before version 0.52 was storing individual project data in the global vim_settings.xml file. This xml file could be synchronized to a publicly accessible GitHub repository.
An issue was discovered in JetBrains TeamCity 2018.2.4. The TeamCity server was not using some security-related HTTP headers. The issue was fixed in TeamCity 2019.1.
JetBrains TeamCity 2019.1 and 2019.1.1 allows cross-site scripting (XSS), potentially making it possible to send an arbitrary HTTP request to a TeamCity server under the name of the currently logged-in user.
JetBrains Kotlin versions before 1.3.30 were resolving artifacts using an http connection during the build process, potentially allowing an MITM attack.
JetBrains Ktor framework (created using the Kotlin IDE template) versions before 1.1.0 were resolving artifacts using an http connection during the build process, potentially allowing an MITM attack. This issue was fixed in Kotlin plugin version 1.3.30.