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TI-2026-29078 Aliases CVE-2026-40300

Zulip: Message edit history visible in "moves only" policy through /api/v1/messages/{id}/history

Priority LOW 26CWE-284Published · Updated

Key facts

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

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-284.

Summary

Zulip is an open-source team collaboration tool. Prior to 12.0, With message_edit_history_visibility_policy set to "moves", /api/v1/messages/{id}/history still returns historical content values, allowing low-privilege users to recover text that was edited away from other users' messages. This vulnerability is fixed in 12.0.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00247 16th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed zulip (zulip): 12.0

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

VendorProductAffected versionsFixed inStatusSource
zulipzulipbefore 12.012.0Patch availableCNA
  • zulip Vendorzulip Affected before 12.0 Fixed in 12.0 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:zulip:zulip_server:10.0:*:*:*:*:*:*:*10.0Vulnerablezulip
  • cpe:2.3:a:zulip:zulip_server:10.0:*:*:*:*:*:*:* Versions 10.0 Vulnerable ·zulip

Remediation

  • Fix · CNA zulip (zulip) Fixed in 12.0

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-40300

References

Exploit 1

  • 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
See all 39 →

Sources

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