CVE-2026-2476highCWE-200

CVE-2026-2476: high-severity vulnerability in Mattermost

MS Teams plugin sensitive config values not properly masked in support packets

Published

Follow this CVE+ Monitor Mattermost+ Monitor github.com/mattermost/mattermost-plugin-msteams

E-mail alert when it lands in KEV, gets a public PoC or its score goes up.

21Vexday Risk Score

No sign of exploitation. No public exploitation artifact known so far.

ssvc Trackcvss 7.6epss 0.2%
Mattermost Plugins versions <=2.0.3.0 fail to properly mask sensitive configuration values which allows an attacker with access to support packets to obtain original plugin settings via exported configuration data. Mattermost Advisory ID: MMSA-2026-00606
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:L/A:N
Affected products
Mattermost · Mattermost
Related CVEs — Mattermost

In the same product, most dangerous first.

CVE-2025-25279CRITICALArbitrary file read in Mattermost Boards via import & export board archiveEPSS 24.2%CVE-2021-37859HIGHReflected XSS in OAuth FlowEPSS 3.3%CVE-2022-3257LOWServer-side Denial of Service while processing a specifically crafted GIF fileEPSS 1.3%CVE-2022-4044MEDIUMAuthenticated user could send multiple requests containing a large Auto Responder Message payload and can crash a Mattermost serverEPSS 1.1%CVE-2022-3147LOWServer-side Denial of Service while processing a specifically crafted JPEG fileEPSS 1.0%CVE-2025-4981CRITICALPath Traversal Leading to RCE by Any Authenticated Mattermost UserEPSS 1.0%