Mattermost versions 11.6.x <= 11.6.1, 11.5.x <= 11.5.4, 10.11.x <= 10.11.15, 10.11.x <= 10.11.16 Mattermost fails to require role-management authorization when setting the scheme_admin flag on group syncable link and patch endpoints, which allows a user with group-link permissions to escalate themselves and group members to team or channel admin via crafted API requests.. Mattermost Advisory ID: MMSA-2026-00665
| Vendor | Product | Version(s) | CPE |
|---|---|---|---|
>= 10.11.0, < 10.11.17CPE matchmatch criteria | cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:* | ||
>= 11.5.0, < 11.5.5CPE matchmatch criteria | cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:* | ||
>= 11.6.0, < 11.6.2CPE matchmatch criteria | cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:* | ||
>= 10.11.0, <= 10.11.15CPE match | cpe:2.3:a:mattermost:mattermost:*:*:*:*:*:*:*:* | ||
>= 10.11.0, <= 10.11.16CPE match | cpe:2.3:a:mattermost:mattermost:*:*:*:*:*:*:*:* |
CVSS version used by this source: 3.1
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.3 Bluesky, 0.1 Mastodon, and 0.2 GitHub mentions.
No media coverage found for this CVE.
The average CVE in this peer group has 0.1 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.
Remediation records are not available for this CVE.