Mattermost 6.0 and earlier fails to sufficiently validate parameters during post creation, which allows authenticated attackers to cause a client-side crash of the web application via a maliciously crafted post.
https://mattermost.com/security-updates/
https://hackerone.com/reports/1253732
Source: Mitre, NVD
Published: 2021-12-17
Updated: 2026-06-17
Base Score: 3.5
Vector: CVSS2#AV:N/AC:M/Au:S/C:N/I:N/A:P
Severity: Low
Base Score: 5.7
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:H
Severity: Medium
EPSS: 0.00351