Medium 5.4Published Nov 14, 2025

CVE-2025-55073MS Teams plugin OAuth allows editing arbitrary posts

Updated under an hour ago (Oct 26, 2026, 4:40 PM ET)

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It affects Mattermost and 1 other product. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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Exploited in the last 30 days

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.

CVSS: 5.4 MEDIUM (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L
Weakness (CWE): CWE-306
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Mattermost
NVD analysis: Analyzed
Record last updated: Nov 14, 2025
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Mattermost Mattermost mattermost:mattermost (from the name)	from 10.11.0 through 10.11.3; from 10.5.0 through 10.5.11; from 10.12.0 through 10.12.0; 11.0.0 not affected; 10.11.4 not affected; 10.5.12 not affected; 10.12.1 not affected	CNA record
mattermost mattermost_server mattermost:mattermost_server	from 10.5.0 before 10.5.12; from 10.11.0 before 10.11.4; from 10.12.0 before 10.12.1	NVD

References

References

https://mattermost.com/security-updates	vendor-advisory

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.