Zulip is an open-source team collaboration tool. When a user moves a Zulip message, they have the option to move all messages in the topic, move only subsequent messages as well, or move just a single message. If the user chose to just move one message, and was moving it from a public stream to a private stream, Zulip would successfully move the message, -- but active users who did not have access to the private stream, but whose client had already received the message, would continue to see the message in the public stream until they reloaded their client. Additionally, Zulip did not remove view permissions on the message from recently-active users, allowing the message to show up in the "All messages" view or in search results, but not in "Inbox" or "Recent conversations" views. While the bug has been present since moving messages between streams was first introduced in version 3.0, this option became much more common starting in Zulip 8.0, when the default option in the picker for moving the very last message in a conversation was changed. This issue is fixed in Zulip Server 8.3. No known workarounds are available.
Zulip is an open-source team collaboration tool. It was discovered by the Zulip development team that active users who had previously been subscribed to a stream incorrectly continued being able to use the Zulip API to access metadata for that stream. As a result, users who had been removed from a stream, but still had an account in the organization, could still view metadata for that stream (including the stream name, description, settings, and an email address used to send emails into the stream via the incoming email integration). This potentially allowed users to see changes to a stream’s metadata after they had lost access to the stream. This vulnerability has been addressed in version 7.5 and all users are advised to upgrade. There are no known workarounds for this issue.
Zulip is an open-source team collaboration tool with topic-based threading that combines email and chat. Users who used to be subscribed to a private stream and have been removed from it since retain the ability to edit messages/topics, move messages to other streams, and delete messages that they used to have access to, if other relevant organization permissions allow these actions. For example, a user may be able to edit or delete their old messages they posted in such a private stream. An administrator will be able to delete old messages (that they had access to) from the private stream. This issue was fixed in Zulip Server version 7.3.
Zulip is an open-source team collaboration tool with unique topic-based threading that combines the best of email and chat to make remote work productive and delightful. The main development branch of Zulip Server from May 2, 2023 and later, including beta versions 7.0-beta1 and 7.0-beta2, is vulnerable to a cross-site scripting vulnerability in tooltips on the message feed. An attacker who can send messages could maliciously craft a topic for the message, such that a victim who hovers the tooltip for that topic in their message feed triggers execution of JavaScript code controlled by the attacker.