ShellCodeX vulnerability brief
MEDIUM
Received
CVE-2026-16047
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
Published 17 Aug 2026, 15:16 UTC
Last modified 17 Aug 2026, 15:16 UTC
01
Attack profile
The conditions required to exploit this vulnerability and its potential impact.
Attack vector
Network
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
None
02
Affected products
Product applicability statements supplied with the NVD record.
NVD has not published structured affected-product data for this record.
03
Weakness classification
CWE categories help security teams group the underlying software weakness.
04
Source references
External advisories, patches and technical reports attached to this CVE record.