23 Oct 2026 15:48:27 UTC
Playbooks run owner channel membership permission bypass
cve-program · CVE-2026-8821 · Published
CVE-2026-8821
Playbooks run owner channel membership permission bypass
CVSS 3.1 7.1 HIGHCheck source for fixed versionsKEV status unknown
cve-program · CVE-2026-8821
PublishedMattermost 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
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Exploitation and risk
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