CVE-2025-27149 Zulip exports can leak private data

Medium 4.6 Published 31 Mar 2025 Updated 31 Mar 2025

Zulip server exports leak private user-agent data and private channel metadata to administrators, exposing sensitive information without consent.

Exploited in the wild: Not known
Login needed: An administrator
Attackable: Over the internet
Victim action needed: A user has to click or open something
Fix: None listed

What is CVE-2025-27149?

CVE-2025-27149 is a medium-severity vulnerability in zulip, published on 31 Mar 2025. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.

Official description

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 any organization on the server was incorrectly included in all three export types, regardless of if they were used to access the exported organization or not. The "public data" and "with consent" exports metadata including the titles of some topics in private channels which the administrator otherwise did not have access to, and none of the users consented to exporting and metadata for which users were in a group DM together. This vulnerability is fixed in 10.0.

Weakness: CWE-497

Which versions are affected by CVE-2025-27149?

It affects 1 product.

Products include Zulip Zulip Server.

How do I fix CVE-2025-27149?

No fix has been published for CVE-2025-27149 yet. Limit exposure of the affected software until one is available.

Is CVE-2025-27149 being exploited?

There is no known exploitation of CVE-2025-27149 in the wild and no public exploit code.

Sources

Also known as GHSA-358p-x39m-99mm.