CVE-2026-93847

Improper post type validation on scheduled post endpoints

Published Oct 26, 2026 CVSS 3.1 · 3.5 Low EPSS < 1% KEV · Not listed
Description
Mattermost versions 11.7.x <= 11.7.10 fail to validate reserved system post types on the scheduled post creation and publication paths which allows an authenticated channel member to publish messages rendering as trusted system events via the scheduled post endpoint.. Mattermost Advisory ID: MMSA-2026-00732

Remediation

Vendor Solution

Update Mattermost to versions 11.11.0, 11.7.11 or higher.

Tracking

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Advisories

No advisories available
References
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Mattermost mattermost Server
CPEs cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*
Vendors & Products Mattermost mattermost Server
Type Values Removed Values Added
First Time appeared Mattermost
Mattermost mattermost
Vendors & Products Mattermost
Mattermost mattermost
Type Values Removed Values Added
Description Mattermost versions 11.7.x <= 11.7.10 fail to validate reserved system post types on the scheduled post creation and publication paths which allows an authenticated channel member to publish messages rendering as trusted system events via the scheduled post endpoint.. Mattermost Advisory ID: MMSA-2026-00732
Title Improper post type validation on scheduled post endpoints
Weaknesses CWE-863
References
Metrics cvssV3_1

{'score': 3.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
Mattermost
Published
Updated
Nov 2, 2026, 7:43 PM
Reserved
Sep 18, 2026, 6:37 PM
Status
Analyzed
Published
Oct 26, 2026, 3:16 PM
Modified
Nov 2, 2026, 8:18 PM