CVE-2026-40300

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

Published May 12, 2026 CVSS 4.0 · 6 Medium EPSS < 1% KEV · Not listed
Description
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Prior to 12.0, With message_edit_history_visibility_policy set to "moves", /api/v1/messages/{id}/history still returns historical content values, allowing low-privilege users to recover text that was edited away from other users' messages.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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared Zulip zulip Server
Weaknesses NVD-CWE-noinfo
CPEs cpe:2.3:a:zulip:zulip_server:10.0:*:*:*:*:*:*:*
Vendors & Products Zulip zulip Server
Metrics cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N'}

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Zulip
Zulip zulip
Vendors & Products Zulip
Zulip zulip
Type Values Removed Values Added
Description 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Prior to 12.0, With message_edit_history_visibility_policy set to "moves", /api/v1/messages/{id}/history still returns historical content values, allowing low-privilege users to recover text that was edited away from other users' messages.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.
Title Zulip: Message edit history visible in "moves only" policy through /api/v1/messages/{id}/history
Weaknesses CWE-284
References
Metrics cvssV4_0

{'score': 6, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
May 13, 2026, 12:44 PM
Reserved
Apr 10, 2026, 8:22 PM
Status
Analyzed
Published
May 12, 2026, 5:16 PM
Modified
Nov 11, 2026, 8:10 PM