CVSS 3.1
4.3 mediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:NCVE-2026-6689
Mattermost versions 11.6.x <= 11.6.1, 11.5.x <= 11.5.4, 10.11.x <= 10.11.15, 10.11.x <= 10.11.16 Fail to enforce PermissionInviteUser when setting AllowOpenInvite or AllowedDomains during team creation (the check was only applied on update/patch), which allows an authenticated user holding PermissionCreateTeam but not PermissionInviteUser on the resulting team to configure invite-controlled team settings (make the team publicly joinable via open invite and/or constrain membership via allowed domains) that they are not permitted to set on an existing team via POST /api/v4/teams with allow_open_invite: true and/or a non-empty allowed_domains in the request body.. Mattermost Advisory ID: MMSA-2026-00655
Severity
- EPSS
- 0.2% chance of exploitation in the next 30 days; higher than 4% of CVEs (scores of 2026-10-31)
- CWE
- CWE-862
- Published
- Modified
- Record from
- the NVD, synced
Affected
- mattermost:mattermost_server
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-c28q-m4gf-vg4q | Go | github.com/mattermost/mattermost-server | >=11.6.0 <11.6.1 | 11.6.1 |
| GHSA-c28q-m4gf-vg4q | Go | github.com/mattermost/mattermost-server | >=11.5.0 <11.5.5 | 11.5.5 |
| GHSA-c28q-m4gf-vg4q | Go | github.com/mattermost/mattermost-server | >=10.11.0 <10.11.17 | 10.11.17 |
| GHSA-c28q-m4gf-vg4q | Go | github.com/mattermost/mattermost/server/v8 | >=8.0.0-20250731163400-5b955468ea1e <8.0.0-20260501144115-7d6816abdfd1 | 8.0.0-20260501144115-7d6816abdfd1 |
| GO-2026-6283 | Go | github.com/mattermost/mattermost-server | >=10.11.0+incompatible <10.11.17+incompatible >=11.5.0+incompatible <11.5.5+incompatible >=11.6.0+incompatible <11.6.1+incompatible | 10.11.17+incompatible, 11.5.5+incompatible, 11.6.1+incompatible |
| GO-2026-6283 | Go | github.com/mattermost/mattermost-server/v5 | all versions | no fix published |
| GO-2026-6283 | Go | github.com/mattermost/mattermost-server/v6 | all versions | no fix published |
| GO-2026-6283 | Go | github.com/mattermost/mattermost/server/v8 | >=8.0.0-20250731163400-5b955468ea1e <8.0.0-20260501144115-7d6816abdfd1 | 8.0.0-20260501144115-7d6816abdfd1 |