CVE-2025-49222 MEDIUM

CVE-2025-49222: Mattermost Shared Channel Upload Type Validation Bypass

Vendor Mattermost
Product Mattermost
Weakness CWE-434 · Unrestricted file upload
Published August 21, 2025
Last update August 21, 2025
View on NVD All CVEs

CVSS base score

6.8/10
Attack vector Network
Attack complexity Low
Privileges required High
User interaction None
Confidentiality High
Integrity None

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:N

What the vulnerability does

01Description

Mattermost versions 10.8.x <= 10.8.3, 10.5.x <= 10.5.8, 9.11.x <= 9.11.17, 10.9.x <= 10.9.2, 10.10.x <= 10.10.0 fail to validate upload types in remote cluster upload sessions which allows a system admin to upload non-attachment file types via shared channels that could potentially be placed in arbitrary filesystem directories.

Key dates

02Disclosure timeline

August 21, 2025 CVE published
August 21, 2025 Record updated