The latest version is supported, as is the last minor version and the last major version.
For example, if they are v1.0.0, v1.0.1, v2.0.0, v2.1.0, v2.2.0, the supported versions are: v1.0.1, v2.1.0, v2.2.0.
For minor security issues, please open an issue and we will get it sorted out as soon as possible.
For major security issues, please email me at [email protected].