CVE-2026-4274
Published: Mar 26, 2026
Modified: Mar 26, 2026
CVSS v3.1
5.4
Description
Mattermost versions 11.2.x <= 11.2.2, 10.11.x <= 10.11.10, 11.4.x <= 11.4.0, 11.3.x <= 11.3.1 fail to restrict team-level access when processing membership sync from a remote cluster, which allows a malicious remote cluster to grant a user access to an entire private team instead of only the shared channel via sending crafted membership sync messages that trigger team membership assignment. Mattermost Advisory ID: MMSA-2026-00574
| Vendor | Product | Versions |
|---|---|---|
Mattermost | Mattermost | affected 11.2.0 - <= 11.2.2affected 10.11.0 - <= 10.11.10affected 11.4.0 - <= 11.4.0affected 11.3.0 - <= 11.3.1unaffected 11.5.0+4 more versions |
Weaknesses (CWE)
CVSS v3.1 Details
CVSS v3.1 Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality
Integrity
Availability
References
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