CVE-2026-3115
Guest users can view group member IDs without respecting view restrictions
CVSS Score
4.3
EPSS Score
0.0%
EPSS Percentile
0th
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 apply view restrictions when retrieving group member IDs, which allows authenticated guest users to enumerate user IDs outside their allowed visibility scope via the group retrieval endpoint.. Mattermost Advisory ID: MMSA-2026-00594
| CWE | CWE-863 |
| Vendor | mattermost |
| Product | mattermost |
| Published | Mar 26, 2026 |
| Last Updated | Mar 26, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
None
Affected Versions
Mattermost / Mattermost
11.2.0 ≤ 11.2.2 10.11.0 ≤ 10.11.10 11.4.0 ≤ 11.4.0 11.3.0 ≤ 11.3.1
Credits
winfunc