Auth bypass in Mattermost Google Drive
CVE-2026-2299
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.
Vulnerability class: Broken Access Control
Published · last modified .
CVSS v3 metric
CVSS v3 base score 4.2 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N.
EPSS exploit prediction
EPSS: 0.001 (2.1th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 2nd percentile — 2.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.001 · newest: 0.001 · change: 0.000
Affected products
- Mattermost Google Drive — versions 1.1.0
- Mattermost Google Drive Plugin — versions 0, 1.1.0
Weakness classification (CWE)
References
- github.com/mattermost/mattermost-plugin-google-drive/releases/tag/v1.1.0 (Product, Release Notes)
Frequently asked questions
- What is CVE-2026-2299?
- CVE-2026-2299 is a medium-severity vulnerability in Mattermost Google Drive, classified under Missing Authorization. CVSS score: 4.2/10. Published 2026-06-25.
- How severe is CVE-2026-2299?
- Medium severity. CVSS v3 base score is 4.2 out of 10.