CVE-2026-18560
Improper order of authorisations in Mattermost GetFile API leads to an authenticated user to determine a post’s quarantined status
CVSS Score
4.3
EPSS Score
0.0%
EPSS Percentile
0th
Mattermost versions 11.10.x <= 11.10.0, 11.7.x <= 11.7.9, 11.9.x <= 11.9.1, 11.8.x <= 11.8.5 fail to validate user’s permissions before other validations which allows non-content reviewers to infer a post’s flagged status via direct API call.. Mattermost Advisory ID: MMSA-2026-00754
| CWE | CWE-203 |
| Vendor | mattermost |
| Product | mattermost |
| Published | Oct 16, 2026 |
Stay Ahead of the Next One
Get instant alerts for mattermost mattermost
Be the first to know when new medium vulnerabilities affecting mattermost mattermost are published — delivered to Slack, Telegram or Discord.
Get Free Alerts →
Free · No credit card · 60 sec setup
CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
None
Affected Versions
Mattermost / Mattermost
11.10.0 ≤ 11.10.0 11.7.0 ≤ 11.7.9 11.9.0 ≤ 11.9.1 11.8.0 ≤ 11.8.5
Credits
adamsec-dev