Public mode

No access to your tenant or devices. Every item links to its source. What this means

Sources need attention Customize Public modeDiscuss ChangeIntel on Discord

Playbooks run owner channel membership permission bypass

CVSS 3.1 7.1 HIGHCheck source for fixed versionsKEV status unknown

cve-program · CVE-2026-8821

Published

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

Read the publisher's advisory

Affected versions, risk and source history

cve-program · CVE-2026-8821

Published

Mattermost

Vendor product

Publisher's version information

Shown as published. These rules are not interpreted as NuGet package version ranges.

{
                    "defaultStatus": "unaffected",
                    "product": "Mattermost",
                    "vendor": "Mattermost",
                    "versions": [
                        {
                            "lessThanOrEqual": "11.9.0",
                            "status": "affected",
                            "version": "11.9.0",
                            "versionType": "semver"
                        },
                        {
                            "lessThanOrEqual": "11.8.4",
                            "status": "affected",
                            "version": "11.8.0",
                            "versionType": "semver"
                        },
                        {
                            "lessThanOrEqual": "11.7.7",
                            "status": "affected",
                            "version": "11.7.0",
                            "versionType": "semver"
                        },
                        {
                            "lessThanOrEqual": "10.11.22",
                            "status": "affected",
                            "version": "10.11.0",
                            "versionType": "semver"
                        },
                        {
                            "version": "11.10.0",
                            "status": "unaffected"
                        },
                        {
                            "version": "11.9.1",
                            "status": "unaffected"
                        },
                        {
                            "version": "11.8.5",
                            "status": "unaffected"
                        },
                        {
                            "version": "11.7.8",
                            "status": "unaffected"
                        },
                        {
                            "version": "10.11.23",
                            "status": "unaffected"
                        }
                    ]
                }

Original source record · Cite this exact observation · Complete original publisher JSON

ChangeIntel

An IT change radar: releases, security, known issues, retirements, documentation changes, and service status from public sources. Every item links to supporting evidence; dates and statuses can change after they are read.

Sources read 13 Nov 17:25 UTC · 274 of 275 readable · 273 fully read · documentation 469/469 current