Mattermost doesn't validate user permissions when creating Jira issues from Mattermost posts
Moderate severity
GitHub Reviewed
Published
Feb 13, 2026
to the GitHub Advisory Database
•
Updated Feb 13, 2026
Package
Affected versions
>= 11.2.0, <= 11.2.1
>= 11.1.0, <= 11.1.2
>= 10.11.0, <= 10.11.9
Patched versions
11.2.2
11.1.3
10.11.10
Description
Published by the National Vulnerability Database
Feb 13, 2026
Published to the GitHub Advisory Database
Feb 13, 2026
Last updated
Feb 13, 2026
Reviewed
Feb 13, 2026
Mattermost versions 11.1.x <= 11.1.2, 10.11.x <= 10.11.9, 11.2.x <= 11.2.1 fail to validate user permissions when creating Jira issues from Mattermost posts, which allows an authenticated attacker with access to the Jira plugin to read post content and attachments from channels they do not have access to via the /create-issue API endpoint by providing the post ID of an inaccessible post.. Mattermost Advisory ID: MMSA-2025-00550
References