CVE-2024-39839

Remote username set to an arbitrary string by remote user

Published Aug 1, 2024 CVSS 3.1 · 4.3 Medium EPSS < 1% KEV · Not listed
Description
Mattermost versions 9.9.x <= 9.9.0, 9.5.x <= 9.5.6, 9.7.x <= 9.7.5, 9.8.x <= 9.8.1 fail to disallow users to set their own remote username, when shared channels were enabled, which allows a user on a remote to set their remote username prop to an arbitrary string, which would be then synced to the local server as long as the user hadn't been synced before.

Remediation

Vendor Solution

Update Mattermost to versions 9.10.0, 9.9.1, 9.5.7, 9.7.6, 9.8.2 or higher.

Tracking

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Advisories

Source ID Title
EUVD EUVD EUVD-2024-2663 Mattermost versions 9.9.x <= 9.9.0, 9.5.x <= 9.5.6, 9.7.x <= 9.7.5, 9.8.x <= 9.8.1 fail to disallow users to set their own remote username, when shared channels were enabled, which allows a user on a remote to set their remote username prop to an arbitrary string, which would be then synced to the local server as long as the user hadn't been synced before.
Github GHSA Github GHSA GHSA-vg6q-84p8-qvqh Mattermost allows a user on a remote to set their remote username prop to an arbitrary string
References
History
Type Values Removed Values Added
First Time appeared Mattermost
Mattermost mattermost Server
Weaknesses NVD-CWE-noinfo
CPEs cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*
cpe:2.3:a:mattermost:mattermost_server:9.9.0:*:*:*:*:*:*:*
Vendors & Products Mattermost
Mattermost mattermost Server
Weaknesses

Sources

Status
PUBLISHED
Assigner
Mattermost
Published
Updated
Aug 1, 2024, 6:04 PM
Reserved
Jul 23, 2024, 6:35 PM
Status
Analyzed
Published
Aug 1, 2024, 3:15 PM
Modified
Jun 17, 2026, 7:42 AM