Discourse is a platform for community discussion. Under certain conditions, a user badge may have been awarded based on a user's activity in a topic with restricted access. Before this vulnerability was disclosed, the topic title of the topic associated with the user badge may be viewed by any user. If there are sensitive information in the topic title, it will therefore have been exposed. This issue is patched in the latest stable, beta and tests-passed versions of Discourse. There are currently no known workarounds available.

Discourse is a platform for community discussion. Users who receive an invitation link that is not scoped to a single email address can enter any non-admin user's email and gain access to their account when accepting the invitation. All users should upgrade to the latest version. A workaround is temporarily disabling invitations with `SiteSetting.max_invites_per_day = 0` or scope them to individual email addresses.

Discourse is a platform for community discussion. A malicious admin could use this vulnerability to perform port enumeration on the local host or other hosts on the internal network, as well as against hosts on the Internet. Latest `stable`, `beta`, and `test-passed` versions are now patched. As a workaround, self-hosters can use `DISCOURSE_BLOCKED_IP_BLOCKS` env var (which overrides `blocked_ip_blocks` setting) to stop webhooks from accessing private IPs.

Discourse is an open source discussion platform. In versions prior to 2.8.9 on the `stable` branch and prior to 2.9.0.beta10 on the `beta` and `tests-passed` branches, a malicious actor can add large payloads of text into the Location and Website fields of a user profile, which causes issues for other users when loading that profile. A fix to limit the length of user input for these fields is included in version 2.8.9 on the `stable` branch and version 2.9.0.beta10 on the `beta` and `tests-passed` branches. There are no known workarounds.

Discourse is an open source discussion platform. In versions prior to 2.8.9 on the `stable` branch and prior to 2.9.0.beta10 on the `beta` and `tests-passed` branches, a moderator can create new and edit existing themes by using the API when they should not be able to do so. The problem is patched in version 2.8.9 on the `stable` branch and version 2.9.0.beta10 on the `beta` and `tests-passed` branches. There are no known workarounds.

Discourse is an open source discussion platform. In versions prior to 2.8.9 on the `stable` branch and prior to 2.9.0.beta10 on the `beta` and `tests-passed` branches, admins can upload a maliciously crafted Zip or Gzip Tar archive to write files at arbitrary locations and trigger remote code execution. The problem is patched in version 2.8.9 on the `stable` branch and version 2.9.0.beta10 on the `beta` and `tests-passed` branches. There are no known workarounds.

Discourse through 2.8.7 allows admins to send invitations to arbitrary email addresses at an unlimited rate.

Discourse is the an open source discussion platform. In affected versions an email activation route can be abused to send mass spam emails. A fix has been included in the latest stable, beta and tests-passed versions of Discourse which rate limits emails. Users are advised to upgrade. Users unable to upgrade should manually rate limit email.

Discourse is the an open source discussion platform. In affected versions a maliciously crafted request for static assets could cause error responses to be cached by Discourse's default NGINX proxy configuration. A corrected NGINX configuration is included in the latest stable, beta and tests-passed versions of Discourse. Users are advised to upgrade. There are no known workarounds for this vulnerability.

Discourse is an open source discussion platform. Under certain conditions, a logged in user can redeem an invite with an email that either doesn't match the invite's email or does not adhere to the email domain restriction of an invite link. The impact of this flaw is aggravated when the invite has been configured to add the user that accepts the invite into restricted groups. Once a user has been incorrectly added to a restricted group, the user may then be able to view content which that are restricted to the respective group. Users are advised to upgrade to the current stable releases. There are no known workarounds to this issue.

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 an open source platform for community discussion. A category's group permissions settings can be viewed by anyone that has access to the category. As a result, a normal user is able to see whether a group has read/write permissions in the category even though the information should only be available to the users that can manage a category. This issue is patched in the latest stable, beta and tests-passed versions of Discourse. There are no workarounds for this problem.

Discourse is an open source platform for community discussion. In affected versions an attacker can poison the cache for anonymous (i.e. not logged in) users, such that the users are shown the crawler view of the site instead of the HTML page. This can lead to a partial denial-of-service. This issue is patched in the latest stable, beta and tests-passed versions of Discourse. There are no known workarounds for this issue.

Discourse is an open source platform for community discussion. In stable versions prior to 2.8.3 and beta versions prior 2.9.0.beta4 erroneously expose groups. When a group with restricted visibility has been used to set the permissions of a category, the name of the group is leaked to any user that is able to see the category. To workaround the problem, a site administrator can remove groups with restricted visibility from any category's permissions setting.

Discourse is an open source discussion platform. Versions 2.8.2 and prior in the `stable` branch, 2.9.0.beta3 and prior in the `beta` branch, and 2.9.0.beta3 and prior in the `tests-passed` branch are vulnerable to a data leak. Users can request an export of their own activity. Sometimes, due to category settings, they may have category membership for a secure category. The name of this secure category is shown to the user in the export. The same thing occurs when the user's post has been moved to a secure category. A patch for this issue is available in the `main` branch of Discourse's GitHub repository and is anticipated to be part of future releases.

Discourse is an open source discussion platform. In versions prior to 2.8.1 in the `stable` branch, 2.9.0.beta2 in the `beta` branch, and 2.9.0.beta2 in the `tests-passed` branch, users can trigger a Denial of Service attack by posting a streaming URL. Parsing Oneboxes in the background job trigger an infinite loop, which cause memory leaks. This issue is patched in version 2.8.1 of the `stable` branch, 2.9.0.beta2 of the `beta` branch, and 2.9.0.beta2 of the `tests-passed` branch. As a workaround, disable onebox in admin panel completely or specify allow list of domains that will be oneboxed.

Discourse is an open source discussion platform. Discourse groups can be configured with varying visibility levels for the group as well as the group members. By default, a newly created group has its visibility set to public and the group's members visibility set to public as well. However, a group's visibility and the group's members visibility can be configured such that it is restricted to logged on users, members of the group or staff users. A vulnerability has been discovered in versions prior to 2.7.13 and 2.8.0.beta11 where the group advanced search option does not respect the group's visibility and members visibility level. As such, a group with restricted visibility or members visibility can be revealed through search with the right search option. This issue is patched in `stable` version 2.7.13, `beta` version 2.8.0.beta11, and `tests-passed` version 2.8.0.beta11 versions of Discourse. There are no workarounds aside from upgrading.

Discourse is an open source discussion platform. Versions prior to 2.7.13 in `stable`, 2.8.0.beta11 in `beta`, and 2.8.0.beta11 in `tests-passed` allow some users to log in to a community before they should be able to do so. A user invited via email to a forum with `must_approve_users` enabled is going to be automatically logged in, bypassing the check that does not allow unapproved users to sign in. They will be able to do everything an approved user can do. If they logout, they cannot log back in. This issue is patched in the `stable` version 2.7.13, `beta` version 2.8.0.beta11, and `tests-passed` version 2.8.0.beta11. One may disable invites as a workaround. Administrators can increase `min_trust_level_to_allow_invite` to reduce the attack surface to more trusted users.

Discourse is an open source discussion platform. Prior to version 2.8.0.beta11 in the `tests-passed` branch, version 2.8.0.beta11 in the `beta` branch, and version 2.7.13 in the `stable` branch, the bios of users who made their profiles private were still visible in the `<meta>` tags on their users' pages. The problem is patched in `tests-passed` version 2.8.0.beta11, `beta` version 2.8.0.beta11, and `stable` version 2.7.13 of Discourse.