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OpenAdvisories
Medium · 4.6 CVE-2026-27659 EUVD-2026-15806GHSA-rmhw-c3xr-m3xxGO-2026-5629

CSRF vulnerability in UpdateAccessControlPolicyActiveStatus endpoint

Published Mar 25, 2026 · Updated Mar 25, 2026 · Assigned by Mattermost

Description

Mattermost versions 11.2.x <= 11.2.2, 10.11.x <= 10.11.10, 11.4.x <= 11.4.0, 11.3.x <= 11.3.1 fail to properly validate CSRF tokens in the /api/v4/access_control_policies/{policy_id}/activate endpoint, which allows an attacker to trick an admin into changing access control policy active status via a crafted request.. Mattermost Advisory ID: MMSA-2026-00578

Affected products

VendorProductAffectedFixed
Mattermost Mattermost 11.2.0 – ≤ 11.2.2, 10.11.0 – ≤ 10.11.10, 11.4.0 – ≤ 11.4.0, 11.3.0 – ≤ 11.3.1 11.5.0

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-server >= 10.11.0-rc1+incompatible, < 10.11.11+incompatible · >= 11.2.0-rc1+incompatible, < 11.2.3+incompatible · >= 11.3.0-rc1+incompatible, < 11.3.2+incompatible · >= 11.4.0-rc1+incompatible, < 11.4.1+incompatible 10.11.11+incompatible, 11.2.3+incompatible, 11.3.2+incompatible, 11.4.1+incompatible GO-2026-5629
Go github.com/mattermost/mattermost-server/v5 all versions — GO-2026-5629
Go github.com/mattermost/mattermost-server/v6 all versions — GO-2026-5629
Go github.com/mattermost/mattermost/server/v8 >= 11.4.0-rc1, < 11.4.1 11.4.1 GHSA-rmhw-c3xr-m3xx
Go github.com/mattermost/mattermost/server/v8 >= 11.3.0-rc1, < 11.3.2 11.3.2 GHSA-rmhw-c3xr-m3xx
Go github.com/mattermost/mattermost/server/v8 >= 11.2.0-rc1, < 11.2.3 11.2.3 GHSA-rmhw-c3xr-m3xx
Go github.com/mattermost/mattermost/server/v8 >= 10.11.0-rc1, < 10.11.11 10.11.11 GHSA-rmhw-c3xr-m3xx
Go github.com/mattermost/mattermost/server/v8 >= 8.0.0-20260105080200-d27a2195068d, < 10.11.11 10.11.11 GHSA-rmhw-c3xr-m3xx
Go github.com/mattermost/mattermost/server/v8 >= 8.0.0-20260105080200-d27a2195068d — GO-2026-5629

Advisories 1

References