File Upload Validation Flaw in Mattermost Products by Mattermost

CVE-2025-49222

What is CVE-2025-49222?

Mattermost versions exhibit a vulnerability related to upload type validation during remote cluster upload sessions. This issue allows system administrators to upload non-attachment file types via shared channels. Consequently, these files may be handled in arbitrary filesystem directories, posing a risk of unintended file exposure and system integrity compromise. It's crucial for users and administrators to be aware of this vulnerability and implement necessary measures to mitigate potential risks.

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