CVE-2026-115574
MediumCVSS 5.3Exploitation Probability (EPSS)
Elevated risk54th percentile - higher than 54% of all known CVEs
Summary
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.
Risk Assessment
Unauthenticated visitors can access users' custom profile data, constituting a confidentiality breach.
Recommendation
Update Zulip to version 12.2 or later, which contains the access control fix for the /json/users endpoint.
Other vulnerabilities in Zulip
See all- 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.
- CVE-2026-25742Medium
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.
Original NVD description (English source)
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.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS