Zulip Server vulnerabilities

CVE-2022-23656 [MEDIUM] CWE-79 CVE-2022-23656: Zulip is an open source team chat app. The `main` development branch of Zulip Server from June 2021 Zulip is an open source team chat app. The `main` development branch of Zulip Server from June 2021 and later is vulnerable to a cross-site scripting vulnerability on the recent topics page. An attacker could maliciously craft a full name for their account and send messages to a topic with several participants; a victim who then opens an overflow tool

CVE-2025-52559 [MEDIUM] CWE-79 CVE-2025-52559: Zulip is an open-source team chat application. From versions 2.0.0-rc1 to before 10.4 in Zulip Serve Zulip is an open-source team chat application. From versions 2.0.0-rc1 to before 10.4 in Zulip Server, the /digest/ URL of a server shows a preview of what the email weekly digest would contain. This URL, though not the digest itself, contains a cross-site scripting (XSS) vulnerability in both topic names and channel names. This issue has been fixed

CVE-2020-10935 [MEDIUM] CWE-79 CVE-2020-10935: Zulip Server before 2.1.3 allows XSS via a Markdown link, with resultant account takeover. Zulip Server before 2.1.3 allows XSS via a Markdown link, with resultant account takeover.

CVE-2023-22735 [MEDIUM] CWE-436 CVE-2023-22735: Zulip is an open-source team collaboration tool. In versions of zulip prior to commit `2f6c5a8` but Zulip is an open-source team collaboration tool. In versions of zulip prior to commit `2f6c5a8` but after commit `04cf68b` users could upload files with arbitrary `Content-Type` which would be served from the Zulip hostname with `Content-Disposition: inline` and no `Content-Security-Policy` header, allowing them to trick other users into executing ar

CVE-2024-21630 [MEDIUM] CVE-2024-21630: Zulip is an open-source team collaboration tool. A vulnerability in version 8.0 is similar to CVE-20 Zulip is an open-source team collaboration tool. A vulnerability in version 8.0 is similar to CVE-2023-32677, but applies to multi-use invitations, not single-use invitation links as in the prior CVE. Specifically, it applies when the installation has configured non-admins to be able to invite users and create multi-use invitations, and has also configured

CVE-2018-9987 [MEDIUM] CWE-79 CVE-2018-9987: In Zulip Server versions 1.5.x, 1.6.x, and 1.7.x before 1.7.2, there was an XSS issue with muting no In Zulip Server versions 1.5.x, 1.6.x, and 1.7.x before 1.7.2, there was an XSS issue with muting notifications.

CVE-2018-9986 [MEDIUM] CWE-79 CVE-2018-9986: In Zulip Server versions before 1.7.2, there were XSS issues with the frontend markdown processor. In Zulip Server versions before 1.7.2, there were XSS issues with the frontend markdown processor.

CVE-2018-9990 [MEDIUM] CWE-79 CVE-2018-9990: In Zulip Server versions before 1.7.2, there was an XSS issue with stream names in topic typeahead. In Zulip Server versions before 1.7.2, there was an XSS issue with stream names in topic typeahead.

CVE-2020-12759 [MEDIUM] CWE-79 CVE-2020-12759: Zulip Server before 2.1.5 allows reflected XSS via the Dropbox webhook. Zulip Server before 2.1.5 allows reflected XSS via the Dropbox webhook.

CVE-2018-9999 [MEDIUM] CWE-79 CVE-2018-9999: In Zulip Server versions before 1.7.2, there was an XSS issue with user uploads and the (default) LO In Zulip Server versions before 1.7.2, there was an XSS issue with user uploads and the (default) LOCAL_UPLOADS_DIR storage backend.

CVE-2020-14194 [MEDIUM] CWE-269 CVE-2020-14194: Zulip Server before 2.1.5 allows reverse tabnapping via a topic header link. Zulip Server before 2.1.5 allows reverse tabnapping via a topic header link.

CVE-2019-19775 [MEDIUM] CWE-601 CVE-2019-19775: The image thumbnailing handler in Zulip Server versions 1.9.0 to before 2.0.8 allowed an open redire The image thumbnailing handler in Zulip Server versions 1.9.0 to before 2.0.8 allowed an open redirect that was visible to logged-in users.

CVE-2023-47642 [MEDIUM] CWE-200 CVE-2023-47642: Zulip is an open-source team collaboration tool. It was discovered by the Zulip development team tha 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

CVE-2017-0881 [MEDIUM] CWE-200 CVE-2017-0881: An error in the implementation of an autosubscribe feature in the check_stream_exists route of the Z An error in the implementation of an autosubscribe feature in the check_stream_exists route of the Zulip group chat application server before 1.4.3 allowed an authenticated user to subscribe to a private stream that should have required an invitation from an existing member to join. The issue affects all previously released versions of the Zulip serve

CVE-2021-30477 [MEDIUM] CVE-2021-30477: An issue was discovered in Zulip Server before 3.4. A bug in the implementation of replies to messag An issue was discovered in Zulip Server before 3.4. A bug in the implementation of replies to messages sent by outgoing webhooks to private streams meant that an outgoing webhook bot could be used to send messages to private streams that the user was not intended to be able to send messages to.

CVE-2021-30478 [MEDIUM] CWE-269 CVE-2021-30478: An issue was discovered in Zulip Server before 3.4. A bug in the implementation of the can_forge_sen An issue was discovered in Zulip Server before 3.4. A bug in the implementation of the can_forge_sender permission (previously is_api_super_user) resulted in users with this permission being able to send messages appearing as if sent by a system bot, including to other organizations hosted by the same Zulip installation.

CVE-2022-41914 [LOW] CWE-200 CVE-2022-41914: Zulip is an open-source team collaboration tool. For organizations with System for Cross-domain Iden Zulip is an open-source team collaboration tool. For organizations with System for Cross-domain Identity Management(SCIM) account management enabled, Zulip Server 5.0 through 5.6 checked the SCIM bearer token using a comparator that did not run in constant time. Therefore, it might theoretically be possible for an attacker to infer the value of the tok

CVE-2025-30369 [LOW] CWE-566 CVE-2025-30369: Zulip is an open-source team collaboration tool. The API for deleting an organization custom profile Zulip is an open-source team collaboration tool. The API for deleting an organization custom profile field is supposed to be restricted to organization administrators, but its handler failed to check that the field belongs to the same organization as the user. Therefore, an administrator of any organization was incorrectly allowed to delete custom prof

CVE-2025-27149 [LOW] CWE-497 CVE-2025-27149: Zulip server provides an open-source team chat that helps teams stay productive and focused. Prior t Zulip server provides an open-source team chat that helps teams stay productive and focused. Prior to 10.0, the data export to organization administrators feature in Zulip leaks private data. The collection of user-agent types identifying specific integrations or HTTP libraries (E.g., ZulipGitlabWebhook, okhttp, or PycURL) that have been used to access

CVE-2021-30487 [LOW] CVE-2021-30487: In the topic moving API in Zulip Server 3.x before 3.4, organization administrators were able to mov In the topic moving API in Zulip Server 3.x before 3.4, organization administrators were able to move messages to streams in other organizations hosted by the same Zulip installation.