Mattermost versions 9.10.x <= 9.10.2, 9.11.x <= 9.11.1 and 9.5.x <= 9.5.9 fail to prevent detailed error messages from being displayed in Playbooks which allows an attacker to generate a large response and cause an amplified GraphQL response which in turn could cause the application to crash by sending a specially crafted request to Playbooks.
Exploitability
AV:NAC:LPR:LUI:NScope
S:UImpact
C:NI:NA:L4.3/CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:LResource Management