Discourse is an open-source discussion platform. Prior to version 2.8.4 in the `stable` branch and version `2.9.0.beta5` in the `beta` and `tests-passed` branches, banner topic data is exposed on login-required sites. This issue is patched in version 2.8.4 in the `stable` branch and version `2.9.0.beta5` in the `beta` and `tests-passed` branches of Discourse. As a workaround, one may disable banners.
Discourse is an open source platform for community discussion. Prior to version 2.8.4 on the `stable` branch and 2.9.0beta5 on the `beta` and `tests-passed` branches, inviting users on sites that use single sign-on could bypass the `must_approve_users` check and invites by staff are always approved automatically. The issue is patched in Discourse version 2.8.4 on the `stable` branch and version `2.9.0.beta5` on the `beta` and `tests-passed` branches. As a workaround, disable invites or increase `min_trust_level_to_allow_invite` to reduce the attack surface to more trusted users.
Discourse is a platform for community discussion. In affected versions any private message that includes a group had its title and participating user exposed to users that do not have access to the private messages. However, access control for the private messages was not compromised as users were not able to view the posts in the leaked private message despite seeing it in their inbox. The problematic commit was reverted around 32 minutes after it was made. Users are encouraged to upgrade to the latest commit if they are running Discourse against the `tests-passed` branch.