// For flags

CVE-2025-49222

Mattermost Shared Channel Upload Type Validation Bypass

Severity Score

6.8
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

Track
*SSVC
Descriptions

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.

*Credits: daw10
CVSS Scores
Attack Vector
Network
Attack Complexity
Low
Privileges Required
High
User Interaction
None
Scope
Changed
Confidentiality
High
Integrity
None
Availability
None
Attack Vector
Network
Attack Complexity
Low
Authentication
Multiple
Confidentiality
Complete
Integrity
None
Availability
None
* Common Vulnerability Scoring System
SSVC
  • Decision:Track
Exploitation
None
Automatable
No
Tech. Impact
Partial
* Organization's Worst-case Scenario
Timeline
  • 2025-07-22 CVE Reserved
  • 2025-08-21 CVE Published
  • 2025-08-21 CVE Updated
  • 2025-08-21 EPSS Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-434: Unrestricted Upload of File with Dangerous Type
CAPEC
References (1)
URL Tag Source
https://mattermost.com/security-updates
URL Date SRC
URL Date SRC
URL Date SRC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Mattermost
Search vendor "Mattermost"
 Mattermost
Search vendor "Mattermost" for product "Mattermost"
 >= 10.8.0 <= 10.8.3
Search vendor "Mattermost" for product "Mattermost" and version " >= 10.8.0 <= 10.8.3"
en
Affected
Mattermost
Search vendor "Mattermost"
 Mattermost
Search vendor "Mattermost" for product "Mattermost"
 >= 10.5.0 <= 10.5.8
Search vendor "Mattermost" for product "Mattermost" and version " >= 10.5.0 <= 10.5.8"
en
Affected
Mattermost
Search vendor "Mattermost"
 Mattermost
Search vendor "Mattermost" for product "Mattermost"
 >= 9.11.0 <= 9.11.17
Search vendor "Mattermost" for product "Mattermost" and version " >= 9.11.0 <= 9.11.17"
en
Affected
Mattermost
Search vendor "Mattermost"
 Mattermost
Search vendor "Mattermost" for product "Mattermost"
 >= 10.9.0 <= 10.9.2
Search vendor "Mattermost" for product "Mattermost" and version " >= 10.9.0 <= 10.9.2"
en
Affected
Mattermost
Search vendor "Mattermost"
 Mattermost
Search vendor "Mattermost" for product "Mattermost"
 10.10.0
Search vendor "Mattermost" for product "Mattermost" and version "10.10.0"
en
Affected