Decidim's devise_invitable gem vulnerable to circumvention of invitation token expiry period

Decidim is a participatory democracy framework. Starting in version 0.4.rc3 and prior to version 2.0.9 of the `devise_invitable` gem, the invites feature allows users to accept the invitation for an unlimited amount of time through the password reset functionality. This issue creates vulnerable dependencies starting in version 0.0.1.alpha3 and prior to versions 0.26.9, 0.27.5, and 0.28.0 of the `decidim,` `decidim-admin`, and `decidim-system` gems. When using the password reset functionality, the `devise_invitable` gem always accepts the pending invitation if the user has been invited. The only check done is if the user has been invited but the code does not ensure that the pending invitation is still valid as defined by the `invite_for` expiry period. Decidim sets this configuration to `2.weeks` so this configuration should be respected. The bug is in the `devise_invitable` gem and should be fixed there and the dependency should be upgraded in Decidim once the fix becomes available. `devise_invitable` to version `2.0.9` and above fix this issue. Versions 0.26.9, 0.27.5, and 0.28.0 of the `decidim,` `decidim-admin`, and `decidim-system` gems contain this fix. As a workaround, invitations can be cancelled directly from the database.