Mattermost versions 10.11.x <= 10.11.3, 10.5.x <= 10.5.11, 10.12.x <= 10.12.0 fail to validate the relationship between the post being updated and the MSTeams plugin OAuth flow which allows an attacker to edit arbitrary posts via a crafted MSTeams plugin OAuth redirect URL.
Advisories
Source ID Title
Github GHSA Github GHSA GHSA-ff85-qw3h-g9vp Mattermost allows an attacker to edit arbitrary posts via a crafted MSTeams plugin OAuth redirect URL
Fixes

Solution

Update Mattermost to versions 11.0.0, 10.11.4, 10.5.12, 10.12.1 or higher.


Workaround

No workaround given by the vendor.

References
History

Wed, 19 Nov 2025 21:45:00 +0000

Type Values Removed Values Added
First Time appeared Mattermost mattermost Server
CPEs cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*
Vendors & Products Mattermost mattermost Server

Sat, 15 Nov 2025 21:30:00 +0000

Type Values Removed Values Added
First Time appeared Mattermost
Mattermost mattermost
Vendors & Products Mattermost
Mattermost mattermost

Fri, 14 Nov 2025 16:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Fri, 14 Nov 2025 08:15:00 +0000

Type Values Removed Values Added
Description Mattermost versions 10.11.x <= 10.11.3, 10.5.x <= 10.5.11, 10.12.x <= 10.12.0 fail to validate the relationship between the post being updated and the MSTeams plugin OAuth flow which allows an attacker to edit arbitrary posts via a crafted MSTeams plugin OAuth redirect URL.
Title MS Teams plugin OAuth allows editing arbitrary posts
Weaknesses CWE-306
References
Metrics cvssV3_1

{'score': 5.4, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: Mattermost

Published:

Updated: 2025-11-14T15:46:58.129Z

Reserved: 2025-10-15T11:16:32.206Z

Link: CVE-2025-55073

cve-icon Vulnrichment

Updated: 2025-11-14T15:46:53.785Z

cve-icon NVD

Status : Analyzed

Published: 2025-11-14T08:15:45.687

Modified: 2025-11-19T21:44:28.477

Link: CVE-2025-55073

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2025-11-15T21:25:34Z

Weaknesses