User Channel Membership Validation Flaw in Mattermost by Mattermost, Inc.

CVE-2025-13767

What is CVE-2025-13767?

A vulnerability in Mattermost allows authenticated users with access to the Jira plugin to exploit inadequate validation of user channel memberships. This security lapse enables attackers to view and access posts and attachments from Mattermost channels they are not authorized to see, presenting significant risks to data confidentiality and integrity. Organizations utilizing Mattermost need to address this issue to safeguard their communications and sensitive information.

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