CVE-2026-8821EPSS p19.6%

CVE-2026-8821CVE-2026-8821

Description

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

Scoring

CVSS 7.1 ()
VectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N
EPSS0.29% probability of exploitation · percentile 19.6% · 2026-10-05T12:00:23Z
Last modified2026-09-16
Sourced from NVD + FIRST.org EPSS. Curated for EU compliance use cases by Adam Lundqvist, Founder at SQUR.