cbcvebase.
CVE-2026-2458
published 2026-03-16

CVE-2026-2458: Mattermost versions 11.3.x <= 11.3.0, 11.2.x <= 11.2.2, 10.11.x <= 10.11.10 fail to properly validate team membership when searching channels which allows a…

medium4.3CVSS 3.1
AVNACLPRLUINSUCLINAN
Mattermost versions 11.3.x <= 11.3.0, 11.2.x <= 11.2.2, 10.11.x <= 10.11.10 fail to properly validate team membership when searching channels which allows a removed team member to enumerate all public channels within a private team via the channel search API endpoint.. Mattermost Advisory ID: MMSA-2025-00568

Affected

14 ranges
VendorProductVersion rangeFixed in
github.commattermost_mattermost-server>= 0 < 5.3.2-0.20260113182106-a18b80ba4c325.3.2-0.20260113182106-a18b80ba4c32
github.commattermost_mattermost-server>= 10.11.0-rc1 < 10.11.1110.11.11
github.commattermost_mattermost-server>= 10.11.0-rc1+incompatible < 10.11.11+incompatible10.11.11+incompatible
github.commattermost_mattermost-server>= 11.2.0-rc1 < 11.2.311.2.3
github.commattermost_mattermost-server>= 11.2.0-rc1+incompatible < 11.2.3+incompatible11.2.3+incompatible
github.commattermost_mattermost-server>= 11.3.0-rc1 < 11.3.111.3.1
github.commattermost_mattermost-server>= 11.3.0-rc1+incompatible < 11.3.1+incompatible11.3.1+incompatible
github.commattermost_mattermost_server_v8>= 0 < 8.0.0-20260113182106-a18b80ba4c328.0.0-20260113182106-a18b80ba4c32
mattermostmattermost10.11.0 – 10.11.10
mattermostmattermost11.2.0 – 11.2.2
mattermostmattermost11.3.0 – 11.3.0
mattermostmattermost_server>= 10.11.0 < 10.11.1110.11.11
mattermostmattermost_server>= 11.2.0 < 11.2.311.2.3
mattermostmattermost_server>= 11.3.0 < 11.3.111.3.1