CVE-2025-11777
Low
Description
Mattermost versions 10.11.x <= 10.11.3, 10.5.x <= 10.5.11 fail to properly validate team membership permissions in the Add Channel Member API which allows users from one team to access user metadata and channel membership information from other teams via the API endpoint
SeverityLow
CVSS3.1
Exploit probability—
Product
Mattermost Server
PublishedNov 13, 2025
First seenNov 13, 2025
Weakness typeCWE-863Incorrect authorization
How to fix
Update
- mattermost mattermost_server10.5.12, 10.11.4 or later
- github.com/mattermost/mattermost-server10.11.4, 10.5.12, 5.3.2-0.20250905150616-ba86dfc5876b, 10.5.12+incompatible, 10.11.4+incompatible or later
- github.com/mattermost/mattermost/server/v88.0.0-20250905150616-ba86dfc5876b, 8.0.0-20251212204551-54f2e9b4afd5 or later
- github.com/mattermost/mattermost5.3.2-0.20250905150616-ba86dfc5876b or later
- github.com/mattermost/mattermost-server/v55.3.2-0.20250905150616-ba86dfc5876b or later
- github.com/mattermost/mattermost-server/v65.3.2-0.20250905150616-ba86dfc5876b or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| mattermost mattermost_server | 10.5.0 ≤ v < 10.5.12, 10.11.0 ≤ v < 10.11.4 | 10.5.12, 10.11.4 |
| github.com/mattermost/mattermost-serverGo | 10.11.0 ≤ v < 10.11.4, 10.5.0 ≤ v < 10.5.12, v < 5.3.2-0.20250905150616-ba86dfc5876b, 10.5.0+incompatible ≤ v < 10.5.12+incompatible, 10.11.0+incompatible ≤ v < 10.11.4+incompatible | 10.11.4, 10.5.12, 5.3.2-0.20250905150616-ba86dfc5876b, 10.5.12+incompatible, 10.11.4+incompatible |
| github.com/mattermost/mattermost/server/v8Go | v < 8.0.0-20250905150616-ba86dfc5876b, v < 8.0.0-20251212204551-54f2e9b4afd5 | 8.0.0-20250905150616-ba86dfc5876b, 8.0.0-20251212204551-54f2e9b4afd5 |
| github.com/mattermost/mattermostGo | v < 5.3.2-0.20250905150616-ba86dfc5876b, No range specified | 5.3.2-0.20250905150616-ba86dfc5876b |
| github.com/mattermost/mattermost-server/v5Go | v < 5.3.2-0.20250905150616-ba86dfc5876b, No range specified | 5.3.2-0.20250905150616-ba86dfc5876b |
| github.com/mattermost/mattermost-server/v6Go | v < 5.3.2-0.20250905150616-ba86dfc5876b, No range specified | 5.3.2-0.20250905150616-ba86dfc5876b |
| github.com/mattermost/mattermost/v5Go | No range specified | — |
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