Medium (4.9) in zulip zulip server. EPSS 0.9% chance of exploitation in the next 30 days.
Zulip is an open-source team collaboration tool. Zulip Server versions 2.1.0 above have a user interface tool, accessible only to server owners and server administrators, which provides a way to download a "public data" export. While this export is only accessible to administrators, in many configurations server administrators are not expected to have access to private messages and private streams. However, the "public data" export which administrators could generate contained the attachment contents for all attachments, even those from private messages and streams. Zulip Server version 5.4 contains a patch for this issue.
Severity
CVSS 3.1
4.9 medium
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N
EPSS
0.9% chance of exploitation in the next 30 days; higher than 60% of CVEs (scores of 2026-10-31)