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OpenAdvisories
Low · 3.1 CVE-2026-4286 EUVD-2026-30750GHSA-gvg4-jhmr-6j23GO-2026-5404

Playbooks Plugin fails to validate team transfers, allowing unauthorized removal of member access via playbook update

Published May 18, 2026 · Updated May 18, 2026 · Assigned by Mattermost

Description

Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13 fail to check if {{team_id}} was being changed when updating playbooks, allowing users with only {{Manage Playbook Configurations}} permission to change a playbook's team, bypassing manage members restriction via PUT api. Mattermost Advisory ID: MMSA-2025-00552

Affected products

VendorProductAffectedFixed
Mattermost Mattermost 11.5.0 – ≤ 11.5.1, 10.11.0 – ≤ 10.11.13 11.6.0

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
openSUSE Leap 16.0 govulncheck-vulndb 0.0.20260723T184607-160000.1.1 openSUSE-SU-2026:21483-1

Affected packages

EcosystemPackageAffectedFixedRecord
Go github.com/mattermost/mattermost-plugin-playbooks < 1.41.1-0.20260213020129-e1d6ec2c94e6 1.41.1-0.20260213020129-e1d6ec2c94e6 GHSA-gvg4-jhmr-6j23
Go github.com/mattermost/mattermost-server >= 10.11.0+incompatible, < 10.11.14+incompatible · >= 11.5.0+incompatible, < 11.5.2+incompatible 10.11.14+incompatible, 11.5.2+incompatible GO-2026-5404
Go github.com/mattermost/mattermost-server/v5 all versions — GO-2026-5404
Go github.com/mattermost/mattermost-server/v6 all versions — GO-2026-5404
Go github.com/mattermost/mattermost/server/v8 >= 11.5.0, < 11.5.2 11.5.2 GHSA-gvg4-jhmr-6j23
Go github.com/mattermost/mattermost/server/v8 >= 10.11.0, < 10.11.14 10.11.14 GHSA-gvg4-jhmr-6j23
Go github.com/mattermost/mattermost/server/v8 all versions — GO-2026-5404

Advisories 1

References