CVE-2026-4265

CVSS Score & Metrics

Base Score

4.3 / 10

Vector String

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

Vulnerability Description

Mattermost versions 11.3.x <= 11.3.0, 11.2.x <= 11.2.2, 10.11.x <= 10.11.10 fail to validate team-specific upload_file permissions which allows a guest user to post files in channels where they lack upload_file permission via uploading files in a team where they have permission and reusing the file metadata in a POST request to a different team. Mattermost Advisory ID: MMSA-2025-00553

Vulnerability Details

Published Date

March 16, 2026

Last Modified

March 18, 2026

CWE ID

CWE-863

Source

NVD

Vendor

mattermost

Product

mattermost_server

External References

https://mattermost.com/security-updates

CVSS Score & Metrics

Vulnerability Description

Vulnerability Details

External References

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