CVE-2025-55073

MS Teams plugin OAuth allows editing arbitrary posts

Published Nov 14, 2025 CVSS 3.1 · 5.4 Medium EPSS < 1% KEV · Not listed
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.

Remediation

Vendor Solution

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

Tracking

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

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

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'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
Mattermost
Published
Updated
Nov 14, 2025, 3:46 PM
Reserved
Oct 15, 2025, 11:16 AM
Status
Analyzed
Published
Nov 14, 2025, 8:15 AM
Modified
Oct 19, 2026, 1:10 PM