Admin RCE via prepackaged plugins by way of misconfigured imports directory

Summary

Mattermost versions 10.8.x <= 10.8.3, 10.5.x <= 10.5.8, 9.11.x <= 9.11.17, 10.10.x <= 10.10.1, 10.9.x <= 10.9.3 fail to validate import directory path configuration which allows admin users to execute arbitrary code via malicious plugin upload to prepackaged plugins directory

Timeline

1. Sep 19, 2025, 7:22 PM UTCCVE published
2. Sep 20, 2025, 3:55 AM UTCCISA SSVC assessment

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

3. Feb 26, 2026, 5:48 PM UTCRecord last updated

Affected versions

• Mattermost Mattermost

  From 10.8.0 · through 10.8.3; From 10.5.0 · through 10.5.8; From 9.11.0 · through 9.11.17; From 10.10.0 · through 10.10.1; From 10.9.0 · through 10.9.3

• github.com/mattermost/mattermost-serverGo

  From 10.8.0 · fixed in 10.8.4

• github.com/mattermost/mattermost-serverGo

  From 10.5.0 · fixed in 10.5.9

• github.com/mattermost/mattermost-serverGo

  From 9.11.0 · fixed in 9.11.18

• github.com/mattermost/mattermost-serverGo

  From 10.10.0 · fixed in 10.10.2

• github.com/mattermost/mattermost-serverGo

  From 10.9.0 · fixed in 10.9.4

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

  fixed in 8.0.0-20250707221302-a8fa77f107ef

• github.com/mattermost/mattermost-serverGo

  From 9.11.0+incompatible · fixed in 9.11.18+incompatible; From 10.5.0+incompatible · fixed in 10.5.9+incompatible; From 10.8.0+incompatible · fixed in 10.8.4+incompatible; From 10.9.0+incompatible · fixed in 10.9.4+incompatible; From 10.10.0+incompatible · fixed in 10.10.2+incompatible

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

  All versions

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

  All versions

References 1