CVE-2025-49222 — Unrestricted File Upload in Mattermost Mattermost-server

CWE-434 — Unrestricted File Upload5 documents4 sources
Severity
6.8MEDIUMNVD
EPSS
0.0%
top 85.65%
CISA KEV
Not in KEV
Exploit
No known exploits
Affected products
6
Github.com Mattermost Mattermost-serverGithub.com Mattermost Mattermost Server V8Mattermost Server+3 more
Timeline
PublishedAug 21
Latest updateAug 29

Description

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.

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:N/I:H/A:NExploitability: 2.3 | Impact: 4.0

Affected Packages6 packages

▶NVDmattermost/mattermost_server9.11.0 — 9.11.18+4
▶Gogithub.com/mattermost_mattermost_server_v8< 8.0.0-20250708173752-d6b35c41f0ae5
▶CVEListV5mattermost/mattermost10.8.0 — 10.8.3+4

🔴Vulnerability Details

4
OSV
Mattermost Fails to Validate Remote Cluster Upload Sessions in github.com/mattermost/mattermost-server↗2025-08-29
▶
OSV
Mattermost Fails to Validate Remote Cluster Upload Sessions↗2025-08-21
▶
CVEList
Mattermost Shared Channel Upload Type Validation Bypass↗2025-08-21
▶
GHSA
Mattermost Fails to Validate Remote Cluster Upload Sessions↗2025-08-21
▶
CVE-2025-49222 — Unrestricted File Upload | cvebase