Zulip is an open-source team collaboration tool. Prior to 12.0, With messageedithistoryvisibilitypolicy set to "moves", /api/v1/messages/{id}/history still returns historical content values, allowing low-privilege users to recover text that was edited away from other users' messages. This vulnerability is fixed in 12.0.
Zulip is an open-source team collaboration tool. From version 1.4.0 to before version 11.6, ./manage.py import reads arbitrary files from the server filesystem via path traversal in uploads/records.json. A crafted export tarball causes the server to copy any file the zulip user can read into the uploads directory during import. This issue has been patched in version 11.6.
Zulip is an open-source team collaboration tool. Prior to version 11.6, Zulip is an open-source team collaboration tool. From version 1.4.0 to before version 11.6, even after spectator access (enablespectatoraccess / WEBPUBLICSTREAMSENABLED) is disabled, attachments originating from web-public streams can still be retrieved anonymously. As a result, file contents remain accessible even after public access is intended to be disabled. Similarly, even after spectator access is disabled, the /users/me/<streamid>/topics endpoint remains reachable anonymously, allowing retrieval of topic history for web-public streams. This issue has been patched in version 11.6. This issue has been patched in version 11.6.
Zulip is an open source team chat application. A weekly cron job (added in 50256f48314250978f521ef439cafa704e056539) demotes channels to being "inactive" after they have not received traffic for 180 days. However, upon doing so, an event was sent to all users in the organization, not just users in the channel. This event contained the name of the private channel. Similarly, the same commit (50256f48314250978f521ef439cafa704e056539) added functionality to notify clients when channels stopped being "inactive." The first message sent to a private channel which had not previously had any messages for over 180 days (and were thus already marked "inactive") would leak an event to all users in the organization; this event also contained the name of the private channel. Commits 75be449d456d29fef27e9d1828bafa30174284b4 and a2a1a7f8d152296c8966f1380872c0ac69e5c87e fixed the issue. This vulnerability only existed in main, and was not part of any published versions.
Zulip contains a regular expression that is vulnerable to ReDoS (Regular Expression Denial of Service).