Read the docs
TI-2021-02864 Aliases CVE-2021-3967GHSA-2xp9-33rm-wcwv

Improper Access Control in zulip/zulip

Priority MEDIUM 40CWE-284Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Security bypass
Confidentiality · integrity · availability
High · High · High
Fix status
Fixed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-284.

Summary

Improper Access Control in GitHub repository zulip/zulip prior to 4.10.

Why it matters now

EPSS 0.00838 58th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed zulip/zulip (zulip): 4.10

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
zulipzulip/zulipbefore 4.104.10Patch availableCNA
  • zulip/zulip Vendorzulip Affected before 4.10 Fixed in 4.10 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:zulip:zulip:*:*:*:*:*:*:*:*before 4.10Vulnerablezulip
  • cpe:2.3:a:zulip:zulip:*:*:*:*:*:*:*:* Versions before 4.10 Vulnerable ·zulip

Remediation

  • Fix · CNA zulip/zulip (zulip) Fixed in 4.10

Timeline

  1. 2026-10-02 Threatist record created from CVE-2021-3967
  2. 2026-10-03 Alias added: GHSA-2xp9-33rm-wcwv

References

Exploit 1

Patch 1

  • 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-2022-16387 Crafted link in Zulip message can cause disclosure of credentials CVSS 3.1HIGH 8.0
See all 19 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences