CVE-2026-95666EPSS p27.4%
CVE-2026-95666CVE-2026-95666
Description
Mattermost versions 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10, 11.10.x <= 11.10.1 fail to limit the length of the post ID array accepted by the bulk reactions endpoint which allows an authenticated user to cause excessive database load via a crafted request to {{POST /api/v4/posts/ids/reactions}}.. Mattermost Advisory ID: MMSA-2026-00771
Scoring
| CVSS | 4.3 () |
| Vector | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L |
| EPSS | 0.36% probability of exploitation · percentile 27.4% · 2026-10-05T12:00:23Z |
| Last modified | 2026-09-22 |