PT-2020-8901 · Mattermost · Mattermost Server

CVE-2018-21258

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Published

2020-06-19

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Updated

2026-07-30

CVSS v3.1

7.5

High

VectorAV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Name of the Vulnerable Software and Affected Versions Mattermost Server versions prior to 5.1
Description An issue in Mattermost Server allows attackers to cause a denial of service via the invite people slash command.
Recommendations For versions prior to 5.1, update to version 5.1 or later to resolve the issue. As a temporary workaround, consider restricting access to the invite people slash command until the update is applied.

Fix

DoS

Special Elements Injection

Resource Exhaustion

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Weakness Enumeration

Related Identifiers

CVE-2018-21258
GHSA-5MH6-P63G-3MV5
GO-2025-4146
OPENSUSE-SU-2026:21483-1
SUSE-SU-2025:4395-1

Affected Products

Mattermost Server