CVE-2026-6961
Published:June 12, 2026
Updated:June 28, 2026
Mattermost versions 11.6.x <= 11.6.1, 11.5.x <= 11.5.4, 10.11.x <= 10.11.15, 10.11.x <= 10.11.16 Mattermost fails to sanitize FileInfo.Name received from federated peers during shared channel file sync, which allows an attacker who controls a federated server to write files to arbitrary locations within the target server's filestore via path traversal sequences in the filename field.. Mattermost Advisory ID: MMSA-2026-00661
Affected Packages
https://github.com/mattermost/mattermost.git (GITHUB):
Affected version(s) >=v10.11.0 <v10.11.16Fix Suggestion:
Update to version v10.11.16https://github.com/mattermost/mattermost.git (GITHUB):
Affected version(s) >=v11.6.0 <v11.6.2Fix Suggestion:
Update to version v11.6.2https://github.com/mattermost/mattermost.git (GITHUB):
Affected version(s) >=v11.5.0 <v11.5.5Fix Suggestion:
Update to version v11.5.5github.com/mattermost/mattermost (GO):
Affected version(s) >=v10.11.0 <v10.11.16Fix Suggestion:
Update to version v10.11.16github.com/mattermost/mattermost (GO):
Affected version(s) >=v11.6.0 <v11.6.2Fix Suggestion:
Update to version v11.6.2github.com/mattermost/mattermost (GO):
Affected version(s) >=v11.5.0 <v11.5.5Fix Suggestion:
Update to version v11.5.5Related Resources (1)
Do you need more information?
Contact UsCVSS v4
Base Score:
8.3
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
HIGH
User Interaction
NONE
Vulnerable System Confidentiality
NONE
Vulnerable System Integrity
HIGH
Vulnerable System Availability
LOW
Subsequent System Confidentiality
NONE
Subsequent System Integrity
HIGH
Subsequent System Availability
LOW
CVSS v3
Base Score:
7.6
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
HIGH
User Interaction
NONE
Scope
CHANGED
Confidentiality
NONE
Integrity
HIGH
Availability
LOW
Weakness Type (CWE)
Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
EPSS
Base Score:
0.29