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

INFO

Published Date :

2026-03-16T12:07:14.659Z

Last Modified :

2026-03-16T13:49:55.080Z

Source :

Mattermost
AFFECTED PRODUCTS

The following products are affected by CVE-2026-4265 vulnerability.

No data.

REFERENCES

Here, you will find a curated list of external links that provide in-depth information to CVE-2026-4265.

URL Resource
https://mattermost.com/security-updates cve-icon cve-icon
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CVSS Vulnerability Scoring System

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