Zulip Server has access control bypass for restrictions on creation of specific channel types
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- None · Low · None
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-863.
Summary
Zulip is an open-source team chat application. Starting in version 10.0 and prior to version 10.3, the "Who can create public channels" access control mechanism can be circumvented by creating a private or web-public channel, and then changing the channel privacy to public. A similar technique works for creating private channels without permission, though such a process requires either the API or modifying the HTML, as we do mark the "private" radio button as disabled in such cases. Version 10.3 contains a patch.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
- Fix · CNA zulip (zulip) Fixed in 10.3
Timeline
- 2026-10-02 Threatist record created from CVE-2025-47930
References
More Zulip vulnerabilities
- TI-2026-20810 Zulip: Anonymous File Access After Disabling Spectator Access CVSS 3.1MEDIUM 5.3
- TI-2026-21062 Zulip: Path Traversal in Import CVSS 3.1MEDIUM 6.1
- TI-2021-19605 RabbitMQ exposes ports with weak default secrets in Zulip Server CVSS 3.1CRITICAL 9.8
- TI-2023-15953 Users who can send invitations can erroneously add users to streams during invitation in Zulip CVSS 3.1LOW 3.1
- TI-2022-13210 Zulip Server insufficient authorization for changing bot roles CVSS 3.1HIGH 8.8
- TI-2021-02864 Improper Access Control in zulip/zulip CVSS 3.1HIGH 8.8
Sources
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences