CVE-2026-25742

Medium

Description

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.

SeverityMedium
CVSS5.3
Exploit probability—
ProductZulip
PublishedApr 3, 2026
First seenApr 3, 2026

How to fix

Update
  • zulip zulip11.6 or later

Affected products

ProductAffected versionsFixed in
zulip zulip1.4.0 ≤ v < 11.611.6

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