CVE-2026-28732

published 2026-05-18

CVE-2026-28732: Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13, 11.4.x <= 11.4.3 Fail to enforce slash command trigger-word uniqueness during command updates which…

Priority P4 24 medium 4.3 CVSS 3.1

AV N AC L PR L UI N S U C N I L A N

Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13, 11.4.x <= 11.4.3 Fail to enforce slash command trigger-word uniqueness during command updates which allows an authenticated team member with Manage Own Slash Commands permission to hijack and impersonate existing system or custom slash commands via editing their own slash command trigger to an already-registered trigger through the command update API. Mattermost Advisory ID: MMSA-2026-00597

Affected

11 ranges

Vendor	Product	Version range	Fixed in
github.com	mattermost_mattermost-server	>= 0 < 5.3.2-0.20260306123948-f5fe8ded6b63	5.3.2-0.20260306123948-f5fe8ded6b63
github.com	mattermost_mattermost_server_v8	>= 0 < 8.0.0-20260306123948-f5fe8ded6b63	8.0.0-20260306123948-f5fe8ded6b63
github.com	mattermost_mattermost_server_v8	>= 10.11.0 < 10.11.14	10.11.14
github.com	mattermost_mattermost_server_v8	>= 11.4.0 < 11.4.4	11.4.4
github.com	mattermost_mattermost_server_v8	>= 11.5.0 < 11.5.2	11.5.2
mattermost	mattermost	10.11.0 – 10.11.13	—
mattermost	mattermost	11.4.0 – 11.4.3	—
mattermost	mattermost	11.5.0 – 11.5.1	—
mattermost	mattermost_server	>= 10.11.0 < 10.11.14	10.11.14
mattermost	mattermost_server	>= 11.4.0 < 11.4.4	11.4.4
mattermost	mattermost_server	>= 11.5.0 < 11.5.2	11.5.2

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CWE-863