CVE-2026-93851High· 8.0▾ TwilightMattermost versions 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10 fail to validate the target post ID in the Agents plugin's mention reminder component, which allows an authenticated user who can post in a channel visible to a sy…
▾ Twilight zone — High severity, or a signal on a lesser flaw
impact 44 · likelihood 0.1 · exploitation 0
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Stakeholder-Specific Vulnerability Categorization from CISA's ADP record at CVE.org: whether exploitation is observed, whether an attack can be automated, and how much of the system is at stake. The CVSS score shown above comes from the assigning CNA record, not NVD.
Disclosure to exploitation, from the record and what we observed since indexing it.
Disclosed via CVEORG
Last analysed / modified upstream
0.3%
Mattermost versions 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10 fail to validate the target post ID in the Agents plugin's mention reminder component, which allows an authenticated user who can post in a channel visible to a system administrator to cause the administrator's browser to send an unintended API request, resulting in replacement of an installed plugin and code execution on the server, via a crafted post containing a forged mention reminder that the administrator clicks. Mattermost Advisory ID: MMSA-2026-00742
Mattermost >= 11.9.0 <= 11.9.1Mattermost >= 11.8.0 <= 11.8.5Mattermost >= 11.7.0 <= 11.7.10Update Mattermost to versions 11.10.0, 11.9.2, 11.8.6, 11.7.11 or higher.
Connected by shared product, vendor, weakness, or advisory.
CVE-2026-93846Low· 3.8Team admin can escalate a team member's permissions via the team member roles endpoint
CVE-2026-93847Low· 3.5Improper post type validation on scheduled post endpoints
CVE-2026-93850Medium· 6.5Unbounded memory consumption during PDF text extraction
CVE-2026-93848Low· 2.7Mattermost OpenID discovery endpoint request bypasses outbound connection filtering, allowing SSRF by a System Administrator
CVE-2026-93849Medium· 6.5Mattermost allows authenticated users to trigger excessive memory allocation via crafted msgpack binary WebSocket frames
CVE-2026-116516Medium· 6.5Insufficient length validation when parsing Zoom chat transcriptions