CVE-2026-6689 — *Missing* {{invite_user}} *permission check on team creation allows unprivileged users to set open-invite and allowed-…

Description (CNA)

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

Affected (CNA)

Vendor / product	Versions
Mattermost / Mattermost	affected 11.6.0 through 11.6.1; affected 11.5.0 through 11.5.4; affected 10.11.0 through 10.11.15; affected 10.11.0 through 10.11.16; unaffected 11.7.0; unaffected 11.6.2; unaffected 11.5.5; unaffected 10.11.16; unaffected 10.11.17

CWE

CWE-862

References

https://mattermost.com/security-updates

ADP enrichment

CISA-ADP

No English description supplied.

No references supplied.