CVE-2026-25742 MEDIUM

CVE-2026-25742: Zulip: Anonymous File Access After Disabling Spectator Access

Vendor Zulip
Product zulip
Weakness CWE-862 · Missing authorization
Published April 3, 2026
Last update April 8, 2026

CVSS base score

5.3/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality Low
Integrity None

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

What the vulnerability does

01Description

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 (enable_spectator_access / WEB_PUBLIC_STREAMS_ENABLED) 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/<stream_id>/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.

Key dates

02Disclosure timeline

April 3, 2026 CVE published
April 8, 2026 Record updated