Missing authorization in Zulip saves draft DMs without access checks
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- High · None · None
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-862.
Summary
Zulip, an open-source team collaboration tool, from 8.0 before 12.2 has a missing authorization check (CWE-862) in organizations that restrict guests from viewing other users. Saving or editing a direct message draft does not verify that the sender can access the draft recipients. An authenticated guest user with low privileges can view profile information of restricted users without sending a message.
Written with Claude Haiku 5.5 from the sources below · 2026-11-04
Description from the CNA
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.
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
Upgrade Zulip to version 12.2, which fixes this issue. Organizations that did not restrict guest access were not affected.
Written with Claude Haiku 5.5 from the sources below · 2026-11-04
- Fix · CNA zulip (zulip) Fixed in 12.2
Timeline
- 2026-11-04 Threatist record created from CVE-2026-115474
- 2026-11-05 CISA SSVC decision points changed
- 2026-11-05 Priority changed: MEDIUM → LOW
References
Other 6
- https://github.com/zulip/zulip/security/advisories/GHSA-vwqp-7j32-xfg5
- https://github.com/zulip/zulip/pull/39913
- https://github.com/zulip/zulip/commit/1127d4cd3cc17a3cc38435ce57ed52b083c33f97
- https://github.com/zulip/zulip/commit/83a4a3a966e6eef11914b80f04426ae114a1970d
- https://github.com/zulip/zulip/releases/tag/12.2
- https://zulip.readthedocs.io/en/latest/overview/changelog.html#zulip-server-12-2
More zulip vulnerabilities
- TI-2024-37129 /api/v1/jwt/fetch_api_key endpoint can leak if an email address has an account in Zulip server CVSS 4.0MEDIUM 6.9
- 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-2022-06082 Multi-use invitations can grant access to other organizations in Zulip 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
Sources
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences