CVE-2026-16047
Medium · 4.3CVSS
4.3
EPSS
0.3%
Published
Aug 17, 2026
CISA due date
—
The record
Mattermost versions 11.7.x <= 11.7.6, 10.11.x <= 10.11.21, 11.8.x <= 11.8.3 fail to validate that users have read access to a channel before linking a board to it, which allows an authenticated attacker to discover the membership of private channels on the same team via creating, patching, importing, or bulk-creating boards with an arbitrary channelId. Mattermost Advisory ID: MMSA-2026-00674
Affected packages
| Ecosystem | Package | Introduced | Fixed |
|---|
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