CVE-2026-25742
MediumCVSS 5.3Exploitation Probability (EPSS)
Low risk24th percentile - higher than 24% of all known CVEs
Summary
In Zulip before version 11.6, even after disabling spectator access, attachments from web-public streams remained anonymously accessible. Additionally, the /users/me/<stream_id>/topics endpoint remained reachable anonymously, allowing retrieval of topic history for those streams.
Risk Assessment
The organization risks unauthorized access to files and topic history that should be protected after disabling public access.
Recommendation
Update Zulip to version 11.6 or later, which contains the fix.
Other vulnerabilities in Zulip
See all- CVE-2026-115574Medium
Zulip is an open-source team collaboration tool. From 11.0 until 12.2, organizations with web-public channels enabled exposed the GET /json/users endpoint to logged-out spectators, and a missing access-control check allowed include_custom_profile_fields=true to return every user's custom profile field values in addition to the documented limited directory data. This exposed those custom profile field values to unauthenticated visitors. This issue is fixed in version 12.2.
- CVE-2026-115474Medium
Zulip is an open-source team collaboration tool. From 8.0 until 12.2, in organizations where the 'Who can view all other users in the organization' setting restricted guests from viewing other users, saving or editing a direct message draft did not verify that the sender could access the draft recipients. A guest could thereby gain access to otherwise restricted users' profile information without sending a message. Organizations that did not restrict guest access were unaffected. This issue is fixed in version 12.2.
- CVE-2026-26058Medium
Zulip before version 11.6 has a path traversal vulnerability in ./manage.py import that allows reading arbitrary files from the server filesystem. A crafted export tarball causes file copying to the uploads directory during import.
Original NVD description (English source)
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.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS