CVE-2026-40300

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Prior to 12.0, With message_edit_history_visibility_policy set to "moves", /api/v1/messages/{id}/history still returns historical content values, allowing low-privilege users to recover text that was edited away from other users' messages.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.

CVSS v3 6.5 MEDIUM

6.5^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.8 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact NONE

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://github.com/zulip/zulip/security/advisories/GHSA-jp8f-mvv6-89cr	Exploit Vendor Advisory
https://github.com/zulip/zulip/security/advisories/GHSA-jp8f-mvv6-89cr	Exploit Vendor Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:zulip:zulip_server:10.0:*:*:*:*:*:*:*

History

13 May 2026, 18:58

Type	Values Removed	Values Added
CVSS	v2 : ~~unknown~~ v3 : ~~unknown~~	v2 : unknown v3 : 6.5
CWE		NVD-CWE-noinfo
First Time		Zulip zulip Server Zulip
CPE		cpe:2.3:a:zulip:zulip_server:10.0:::::::*
References	~~() https://github.com/zulip/zulip/security/advisories/GHSA-jp8f-mvv6-89cr -~~	() https://github.com/zulip/zulip/security/advisories/GHSA-jp8f-mvv6-89cr - Exploit, Vendor Advisory

13 May 2026, 16:00

Type	Values Removed	Values Added
References	~~() https://github.com/zulip/zulip/security/advisories/GHSA-jp8f-mvv6-89cr -~~	() https://github.com/zulip/zulip/security/advisories/GHSA-jp8f-mvv6-89cr -

12 May 2026, 17:16

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-05-12 17:16

Updated : 2026-05-13 18:58

NVD link : CVE-2026-40300

Mitre link : CVE-2026-40300

CVE.ORG link : CVE-2026-40300

JSON object : View

Products Affected

zulip

zulip_server

CWE

CWE-284

Improper Access Control

NVD-CWE-noinfo

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