CVE-2025-12756: GO-2025-4172 - Mattermost fails to validate user permissions when deleting comments in Boards in github.com/mattermost/mattermost
CVE-2025-12756 · Severity: medium · CVSS 4.3 · Published 2025-12-01
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 validate user permissions when deleting comments in Boards, which allows an authenticated user with the editor role to delete comments created by other users.
No. Junglewise Threat Intelligence has no report of CVE-2025-12756 being exploited in the wild.
How severe is CVE-2025-12756?
Medium severity, with a CVSS score of 4.3, published 1 December 2025.
Which products and versions are affected?
github.com/mattermost/mattermost (Go) SEMVER:introduced=0, SEMVER:introduced=10.11.0,last_affected=10.11.4; github.com/mattermost/mattermost-server (Go) SEMVER:introduced=0; github.com/mattermost/mattermost-server/v5 (Go) SEMVER:introduced=0; github.com/mattermost/mattermost-server/v6 (Go) SEMVER:introduced=0; and 1 more.
Is there a fix for CVE-2025-12756?
No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
Am I affected by CVE-2025-12756?
Check whether you run github.com/mattermost/mattermost (Go), github.com/mattermost/mattermost-server (Go), github.com/mattermost/mattermost-server/v5 (Go) or one of the others listed at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.