Members Without Guest Invite Permissions Can Add Guests to Teams

Summary

Mattermost versions 10.6.x <= 10.6.1, 10.5.x <= 10.5.2, 10.4.x <= 10.4.4, 9.11.x <= 9.11.11 fail to check the correct permissions which allows authenticated users who only have permission to invite non-guest users to a team to add guest users to that team via the API to add a single user to a team.

Timeline

1. May 15, 2025, 10:43 AM UTCCVE published
2. May 15, 2025, 1:39 PM UTCCISA SSVC assessment

   Exploitation: none · Automatable: no · Technical impact: partial

3. May 15, 2025, 1:41 PM UTCRecord last updated

Affected versions

• Mattermost Mattermost

  From 10.6.0 · through 10.6.1; From 10.5.0 · through 10.5.2; From 10.4.0 · through 10.4.4; From 9.11.0 · through 9.11.11

• github.com/mattermost/mattermost-serverGo

  From 9.11.0+incompatible · fixed in 9.11.12+incompatible; From 10.4.0+incompatible · fixed in 10.4.5+incompatible; From 10.5.0+incompatible · fixed in 10.5.3+incompatible; From 10.6.0+incompatible · fixed in 10.6.2+incompatible

• github.com/mattermost/mattermost-server/v5Go

  All versions

• github.com/mattermost/mattermost-server/v6Go

  All versions

• github.com/mattermost/mattermost/server/v8Go

  fixed in 8.0.0-20250415054241-76ab3867b785

• github.com/mattermost/mattermost/server/v8Go

  From 10.6.0 · fixed in 10.6.2

• github.com/mattermost/mattermost/server/v8Go

  From 10.5.0 · fixed in 10.5.3

• github.com/mattermost/mattermost/server/v8Go

  From 10.4.0 · fixed in 10.4.5

• github.com/mattermost/mattermost/server/v8Go

  From 9.11.0 · fixed in 9.11.12

References 1