HIGH 7.1 NVD

CVE-2026-8821

Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 fail to validate channel member-management permission during playb

Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 fail to validate channel member-management permission during playbook run creation, allowing an authenticated channel member to add an arbitrary user to a restricted channel via the run owner field.. Mattermost Advisory ID: MMSA-2026-00677

References

https://mattermost.com/security-updates

Published: 2026-09-14 · Source: NVD · Feed updated: 2026-09-15

This high severity vulnerability with a CVSS score of 7.1 was published on 2026-09-14 via NVD.

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