Description
Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13, 11.4.x <= 11.4.3 fail to check the create_post channel permission during post edit operations which allows an authenticated attacker with revoked posting privileges to modify their existing posts via direct API requests to the post update and patch endpoints.. Mattermost Advisory ID: MMSA-2026-00627
Published: 2026-05-18
Score: 4.3 Medium
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

Analysis and contextual insights are available on OpenCVE Cloud.

Remediation

Vendor Solution

Update Mattermost to versions 11.6.0, 11.5.2, 10.11.14, 11.4.4 or higher.

Tracking

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Advisories
Source ID Title
Github GHSA Github GHSA GHSA-v549-xx3c-6pc8 Mattermost doesn't check the create_post channel permission during post edit operations
References
History

Tue, 19 May 2026 17:45:00 +0000

Type Values Removed Values Added
First Time appeared Mattermost mattermost Server
CPEs cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*
Vendors & Products Mattermost mattermost Server

Mon, 18 May 2026 15:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

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


Mon, 18 May 2026 09:45:00 +0000

Type Values Removed Values Added
First Time appeared Mattermost
Mattermost mattermost
Vendors & Products Mattermost
Mattermost mattermost

Mon, 18 May 2026 08:00:00 +0000

Type Values Removed Values Added
Description Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13, 11.4.x <= 11.4.3 fail to check the create_post channel permission during post edit operations which allows an authenticated attacker with revoked posting privileges to modify their existing posts via direct API requests to the post update and patch endpoints.. Mattermost Advisory ID: MMSA-2026-00627
Title Mattermost fails to enforce create_post permission when editing posts
Weaknesses CWE-862
References
Metrics cvssV3_1

{'score': 4.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N'}


Subscriptions

Mattermost Mattermost Mattermost Server
cve-icon MITRE

Status: PUBLISHED

Assigner: Mattermost

Published:

Updated: 2026-05-18T14:35:00.560Z

Reserved: 2026-03-06T12:07:05.977Z

Link: CVE-2026-3637

cve-icon Vulnrichment

Updated: 2026-05-18T14:34:56.006Z

cve-icon NVD

Status : Analyzed

Published: 2026-05-18T08:16:14.040

Modified: 2026-06-17T10:43:54.373

Link: CVE-2026-3637

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-05-18T09:30:22Z

Weaknesses