CVE-2026-93851
Mattermost versions 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10 fail to validate the target post ID in the Agents plugin's mention reminder component…
Impact
Mattermost versions 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10 fail to validate the target post ID in the Agents plugin's mention reminder component, which allows an authenticated user who can post in a channel visible to a system administrator to cause the administrator's browser to send an unintended API request, resulting in replacement of an installed plugin and code execution on the server, via a crafted post containing a forged mention reminder that the administrator clicks. Mattermost Advisory ID: MMSA-2026-00742
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Mattermost | Mattermost | through 11.9.1 |
| 11.8.X | through 11.8.5 | |
| 11.7.X | through 11.7.10 |
Versions were read from the advisory text. No structured product data has been published for this record yet.