CVE-2026-2299

EUVD-2026-39540
The Mattermost Google Drive plugin before version 1.1.0 fails to validate channel membership in the file creation endpoint, allowing authenticated users with a connected Google account to share Google Drive files to unauthorized private channels and disclose private channel membership.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
4.2 MEDIUM
NETWORK
HIGH
LOW
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N