Webhook Secret Exposure via Timing attack in MSteams plugin

Open Source Vulnerabilities CVE-2025-27936

Mattermost Plugin MSTeams versions <2.1.0 and Mattermost Server versions 10.5.x <=10.5.1 with the MS Teams plugin enabled fail to perform constant time comparison on a MSTeams plugin webhook secret which allows an attacker to retrieve the webhook secret of the MSTeams plugin via a timing attack during webhook secret comparison.

Open Source Vulnerabilities GO-2025-3618

Mattermost vulnerable to Observable Timing Discrepancy in github.com/mattermost/mattermost-plugin-msteams. 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-plugin-msteams before v2.1.0.

Open Source Vulnerabilities GHSA-2j87-p623-8cc2

Mattermost Plugin MSTeams versions <2.1.0 and Mattermost Server versions 10.5.x <=10.5.1 with the MS Teams plugin enabled fail to perform constant time comparison on a MSTeams plugin webhook secret which allows an attacker to retrieve the webhook secret of the MSTeams plugin via a timing attack during webhook secret comparison.