Mattermost fails to sanitize team email addresses in github.com/mattermost/mattermost-server
Mattermost fails to sanitize team email addresses in github.com/mattermost/mattermost-server. NOTE: The source advisory for this report contains additional versions that could not be automatically mapped to standard Go module versions. (If this is causing false-positive reports from vulnerability scanners, please suggest an edit to the report.) The additional affected modules and versions are: github.com/mattermost/mattermost-server from v10.5.0 before v10.5.13, from v10.11.0 before v10.11.5, from v10.12.0 before v10.12.2, from v11.0.0 before v11.0.3.
02 / AFFECTED SOFTWARE
Affected packages
116 explicit affected versions
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
Mattermost versions 11.0.x <= 11.0.2, 10.12.x <= 10.12.1, 10.11.x <= 10.11.4, 10.5.x <= 10.5.12 fail to sanitize team email addresses to be visible only to Team Admins, which allows any authenticated user to view team email addresses via the GET /api/v4/channels/{channel_id}/common_teams endpoint
Mattermost fails to sanitize team email addresses in github.com/mattermost/mattermost-server. NOTE: The source advisory for this report contains additional versions that could not be automatically mapped to standard Go module versions. (If this is causing false-positive reports from vulnerability scanners, please suggest an edit to the report.) The additional affected modules and versions are: github.com/mattermost/mattermost-server from v10.5.0 before v10.5.13, from v10.11.0 before v10.11.5, from v10.12.0 before v10.12.2, from v11.0.0 before v11.0.3.
Mattermost versions 11.0.x <= 11.0.2, 10.12.x <= 10.12.1, 10.11.x <= 10.11.4, 10.5.x <= 10.5.12 fail to sanitize team email addresses to be visible only to Team Admins, which allows any authenticated user to view team email addresses via the GET /api/v4/channels/{channel_id}/common_teams endpoint
05 / REFERENCES
Further evidence
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/12xxx/CVE-2025-12559.json
- https://mattermost.com/security-updates
- https://nvd.nist.gov/vuln/detail/CVE-2025-12559
- https://github.com/advisories/GHSA-4g87-9x45-cx2h
- https://github.com/mattermost/mattermost/commit/5d8719042c1807da59ac8a821624eb01152d8495
- https://github.com/mattermost/mattermost/commit/649aee8fa9184ca59bd66022a33b8f8918e413aa
- https://github.com/mattermost/mattermost/commit/7ccb62db7958abd6a4b21a06c5a4f5367a8f8b1f
- https://github.com/mattermost/mattermost/commit/9f54e5cdc3aef412945ff0e6a58338f7b549bdda
- https://github.com/mattermost/mattermost/commit/abbf01b9db45d1850eaf3701ea8362b910193ffd
- https://github.com/mattermost/mattermost/pull/34110
- https://github.com/mattermost/mattermost