medium6.5
CVE-2025-20621
Mattermost webapp crash via a crafted post
Impact
Mattermost versions 10.2.x <= 10.2.0, 9.11.x <= 9.11.5, 10.0.x <= 10.0.3, 10.1.x <= 10.1.3 fail to properly handle posts with attachments containing fields that cannot be cast to a String, which allows an attacker to cause the webapp to crash via creating and sending such a post to a channel.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| go | github.com/mattermost/mattermost/server/v8 | >= 10.2.0, < 10.2.1 | 10.2.1 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Mattermost | Mattermost Server | from 9.11.0 before 9.11.6 from 10.0.0 before 10.0.4 from 10.1.0 before 10.1.4 Version 10.2.0 |