Improper authorization in Zulip Server
Priority LOW 31CWE-285Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- None · High · None
- Fix status
- No fix listed
Attack profile from CVSS 3.0 · NVD. Fix status from CNA. Impact type from CWE-285.
Summary
Zulip Server 1.5.1 and below suffer from an error in the implementation of the invite_by_admins_only setting in the Zulip group chat application server that allowed an authenticated user to invite other users to join a Zulip organization even if the organization was configured to prevent this.
Why it matters now
EPSS 0.01278 70th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| zulip | Zulip Server | up to 1.5.1 | — | No fix listed | CNA |
- Zulip Server Vendorzulip Affected up to 1.5.1 Fixed in — No fix listed CNA
CPE configurations NVD · 19
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:zulip:zulip_server:1.3.0:*:*:*:*:*:*:* | 1.3.0 | Vulnerable | zulip |
| cpe:2.3:a:zulip:zulip_server:1.3.1:*:*:*:*:*:*:* | 1.3.1 | Vulnerable | zulip |
| cpe:2.3:a:zulip:zulip_server:1.3.2:*:*:*:*:*:*:* | 1.3.2 | Vulnerable | zulip |
| cpe:2.3:a:zulip:zulip_server:1.3.3:*:*:*:*:*:*:* | 1.3.3 | Vulnerable | zulip |
| cpe:2.3:a:zulip:zulip_server:1.3.4:*:*:*:*:*:*:* | 1.3.4 | Vulnerable | zulip |
| cpe:2.3:a:zulip:zulip_server:1.3.6:*:*:*:*:*:*:* | 1.3.6 | Vulnerable | zulip |
| cpe:2.3:a:zulip:zulip_server:1.3.7:*:*:*:*:*:*:* | 1.3.7 | Vulnerable | zulip |
| cpe:2.3:a:zulip:zulip_server:1.3.8:*:*:*:*:*:*:* | 1.3.8 | Vulnerable | zulip |
| cpe:2.3:a:zulip:zulip_server:1.3.9:*:*:*:*:*:*:* | 1.3.9 | Vulnerable | zulip |
| cpe:2.3:a:zulip:zulip_server:1.3.10:*:*:*:*:*:*:* | 1.3.10 | Vulnerable | zulip |
- cpe:2.3:a:zulip:zulip_server:1.3.0:*:*:*:*:*:*:* Versions 1.3.0 Vulnerable ·zulip
- cpe:2.3:a:zulip:zulip_server:1.3.1:*:*:*:*:*:*:* Versions 1.3.1 Vulnerable ·zulip
- cpe:2.3:a:zulip:zulip_server:1.3.2:*:*:*:*:*:*:* Versions 1.3.2 Vulnerable ·zulip
- cpe:2.3:a:zulip:zulip_server:1.3.3:*:*:*:*:*:*:* Versions 1.3.3 Vulnerable ·zulip
- cpe:2.3:a:zulip:zulip_server:1.3.4:*:*:*:*:*:*:* Versions 1.3.4 Vulnerable ·zulip
- cpe:2.3:a:zulip:zulip_server:1.3.6:*:*:*:*:*:*:* Versions 1.3.6 Vulnerable ·zulip
- cpe:2.3:a:zulip:zulip_server:1.3.7:*:*:*:*:*:*:* Versions 1.3.7 Vulnerable ·zulip
- cpe:2.3:a:zulip:zulip_server:1.3.8:*:*:*:*:*:*:* Versions 1.3.8 Vulnerable ·zulip
- cpe:2.3:a:zulip:zulip_server:1.3.9:*:*:*:*:*:*:* Versions 1.3.9 Vulnerable ·zulip
- cpe:2.3:a:zulip:zulip_server:1.3.10:*:*:*:*:*:*:* Versions 1.3.10 Vulnerable ·zulip
Show 9 more CPE
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:zulip:zulip_server:1.3.11:*:*:*:*:*:*:* | 1.3.11 | Vulnerable | zulip |
| cpe:2.3:a:zulip:zulip_server:1.3.12:*:*:*:*:*:*:* | 1.3.12 | Vulnerable | zulip |
| cpe:2.3:a:zulip:zulip_server:1.3.13:*:*:*:*:*:*:* | 1.3.13 | Vulnerable | zulip |
| cpe:2.3:a:zulip:zulip_server:1.4.0:*:*:*:*:*:*:* | 1.4.0 | Vulnerable | zulip |
| cpe:2.3:a:zulip:zulip_server:1.4.1:*:*:*:*:*:*:* | 1.4.1 | Vulnerable | zulip |
| cpe:2.3:a:zulip:zulip_server:1.4.2:*:*:*:*:*:*:* | 1.4.2 | Vulnerable | zulip |
| cpe:2.3:a:zulip:zulip_server:1.4.3:*:*:*:*:*:*:* | 1.4.3 | Vulnerable | zulip |
| cpe:2.3:a:zulip:zulip_server:1.5.0:*:*:*:*:*:*:* | 1.5.0 | Vulnerable | zulip |
| cpe:2.3:a:zulip:zulip_server:1.5.1:*:*:*:*:*:*:* | 1.5.1 | Vulnerable | zulip |
- cpe:2.3:a:zulip:zulip_server:1.3.11:*:*:*:*:*:*:* Versions 1.3.11 Vulnerable ·zulip
- cpe:2.3:a:zulip:zulip_server:1.3.12:*:*:*:*:*:*:* Versions 1.3.12 Vulnerable ·zulip
- cpe:2.3:a:zulip:zulip_server:1.3.13:*:*:*:*:*:*:* Versions 1.3.13 Vulnerable ·zulip
- cpe:2.3:a:zulip:zulip_server:1.4.0:*:*:*:*:*:*:* Versions 1.4.0 Vulnerable ·zulip
- cpe:2.3:a:zulip:zulip_server:1.4.1:*:*:*:*:*:*:* Versions 1.4.1 Vulnerable ·zulip
- cpe:2.3:a:zulip:zulip_server:1.4.2:*:*:*:*:*:*:* Versions 1.4.2 Vulnerable ·zulip
- cpe:2.3:a:zulip:zulip_server:1.4.3:*:*:*:*:*:*:* Versions 1.4.3 Vulnerable ·zulip
- cpe:2.3:a:zulip:zulip_server:1.5.0:*:*:*:*:*:*:* Versions 1.5.0 Vulnerable ·zulip
- cpe:2.3:a:zulip:zulip_server:1.5.1:*:*:*:*:*:*:* Versions 1.5.1 Vulnerable ·zulip
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2017-0896
- 2026-10-03 Alias added: GHSA-98x3-p3h4-w982
References
More Zulip Server 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-2022-06082 Multi-use invitations can grant access to other organizations in Zulip CVSS 3.1CRITICAL 9.8
- TI-2019-13649 In Zulip Server versions from 1.7.0 to before 2.0.7, a bug in the new user signup process… CVSS 3.1CRITICAL 9.8
- TI-2025-22659 Zulip Authentication Backend Configuration Bypass CVSS 3.1HIGH 8.2
- TI-2024-24345 Zulip from 8.0 to 8.3 contains a memory leak vulnerability in the handling of popovers. CVSS 3.1HIGH 7.5
- TI-2020-11848 Zulip Server 2.x before 2.1.7 allows eval injection if a privileged attacker were able to… CVSS 3.1HIGH 8.8
Sources
- CVE-2017-0896 · CVE Program
- CVE-2017-0896 · NVD
- FIRST EPSS
- GHSA-98x3-p3h4-w982 · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences