CVE-2026-28732CWE-863broken-access-control

CVE-2026-28732

Medium · published May 18, 2026

CVSS v3.1
4.3
EPSS
0%
Percentile
16.0
In the wild
Unconfirmed
What it is

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

The record
Technical detail
CVSS v3.1
4.3 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
CVSS v4.0
Not supplied
EPSS
0.00254 · 16.0th percentile
Weakness
CWE-863 · Incorrect Authorization
Published
2026-05-18T13:16Z
Affected products (3)
ProductVersionsFixed in
mattermost/mattermost_server≥ 10.11.0, < 10.11.1410.11.14
mattermost/mattermost_server≥ 11.4.0, < 11.4.411.4.4
mattermost/mattermost_server≥ 11.5.0, < 11.5.211.5.2
References (1)
https://mattermost.com/security-updates · [email protected]
EPSS history
Timeline
  • 18 MAY 08:35Z
    Slash command trigger-word update allowed command hijacking
    cvelistv5