CVE-2026-27659

Discovered by AISLEPUBLISHEDCWE-352

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

CVSS Base Scores

CVSS v3.1(Primary)
4.6

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N

Affected Products

VendorProductVersionStatus
MattermostMattermost11.2.0affected
MattermostMattermost10.11.0unaffected
MattermostMattermost11.4.0—
MattermostMattermost11.3.0—
MattermostMattermost11.5.0—
MattermostMattermost11.2.3—
MattermostMattermost10.11.11—
MattermostMattermost11.4.1—
MattermostMattermost11.3.2—

Credits

  • Joshua Rogers(finder)

Solutions

Update Mattermost to versions 11.5.0, 11.2.3, 10.11.11, 11.4.1, 11.3.2 or higher.

References