CVE-2026-18560: Improper order of authorisations in Mattermost GetFile API leads to an authenticated user to determine a post’s quarantined status
Medium · CVSS 4.3 (CVSS 3.1)EPSS 0.18%, 7th percentilePublished Updated Assigner: Mattermost
Description
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
Vector CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N · CWE-203
Tracked companies
Mapped from the CVE’s affected-product data, NVD CPE matches, vendor advisories or package feeds. A mapping means the vendor’s software is named, not that its hosted service was exposed.
Status incidents that name it
No tracked status incident names this CVE.
Affected vendors and products
Mattermost: Mattermost
References
- CVE record on cve.org (opens in new tab)
- NVD entry (opens in new tab)
- mattermost.com/security-updates (opens in new tab)
- CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (opens in new tab)
- This product uses data from the NVD API but is not endorsed or certified by the NVD. (opens in new tab)
- Known Exploited Vulnerabilities catalog from CISA. (opens in new tab)
- EPSS scores from FIRST (Exploit Prediction Scoring System). (opens in new tab)