CVE-2026-3636 - Vulnerability Details - OpenCVE

Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to sanitize team member data when returned via API to users without elevated permissions which allows a user without permissions to get data about team members roles via invoking various team API endpoints.. Mattermost Advisory ID: MMSA-2026-00626

No CVSS v4.0

Attack Vector Network

Attack Complexity Low

Privileges Required Low

Scope Unchanged

Confidentiality Impact Low

Integrity Impact None

Availability Impact None

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

The EPSS score is 0.00022.

Exploitation none

Automatable no

Technical Impact partial

Vendors	Products
Mattermost	Mattermost

No data.

No data.

OpenCVE Enrichment is a feature of OpenCVE that uses AI to automatically link vendors and products to CVEs. Learn more on GitHub.

Vendors	Products
Mattermost	Mattermost

References

Link	Providers
https://mattermost.com/security-updates

History

Fri, 22 May 2026 13:30:00 +0000

Type	Values Removed	Values Added
Metrics		ssvc `{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}`

Fri, 22 May 2026 13:15:00 +0000

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

Fri, 22 May 2026 11:00:00 +0000

Type	Values Removed	Values Added
Description		Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to sanitize team member data when returned via API to users without elevated permissions which allows a user without permissions to get data about team members roles via invoking various team API endpoints.. Mattermost Advisory ID: MMSA-2026-00626
Title		Sanitize team member data returned by API
Weaknesses		CWE-200
References		https://mattermost.com/security-updates
Metrics		cvssV3_1 `{'score': 4.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N'}`

MITRE

Status: PUBLISHED

Assigner: Mattermost

Published: 2026-05-22T10:23:20.485Z

Updated: 2026-05-22T12:13:43.868Z

Reserved: 2026-03-06T09:40:10.820Z

Link: CVE-2026-3636

Vulnrichment

Updated: 2026-05-22T12:13:39.934Z

NVD

No data.

Redhat

No data.

OpenCVE Enrichment

Updated: 2026-05-22T13:00:13Z

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