# Security Policy ## Supported Versions We are following [*CalVer*](https://calver.org) with generous backwards-compatibility guarantees. Therefore we only support the latest version. Put simply, you shouldn't ever be afraid to upgrade as long as you're only using our public APIs. Whenever there is a need to break compatibility, it is announced in the changelog, and raises a `DeprecationWarning` for a year (if possible) before it's finally really broken. > **Warning** > The structure of the `attrs.Attribute` class is exempt from this rule. > It *will* change in the future, but since it should be considered read-only, that shouldn't matter. > > However if you intend to build extensions on top of *attrs* you have to anticipate that. ## Reporting a Vulnerability To report a security vulnerability, please use the [Tidelift security contact](https://tidelift.com/security). Tidelift will coordinate the fix and disclosure.