An issue was discovered in Mattermost Server before 5.18.0. An attacker can send a user_typing WebSocket event to any channel.
{
"cpe": "cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*",
"source": "CPE_RANGE",
"extracted_events": [
{
"introduced": "0"
},
{
"fixed": "5.18.0"
}
]
}