medium5.3
CVE-2025-27936
Mattermost vulnerable to Observable Timing Discrepancy
Impact
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.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| go | github.com/mattermost/mattermost/server/v8 | >= 10.5.0, < 10.5.2 | 10.5.2 |
| go | github.com/mattermost/mattermost-plugin-msteams | <= 1.15.0 | 2.1.0 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Mattermost | Mattermost Server | before 10.5.2 |
| Mattermost | Ms Teams | before 2.1.0 |