Mattermost versions 11.0.x <= 11.0.4, 10.12.x <= 10.12.2, 10.11.x <= 10.11.6 fail to check WebSocket request field for proper UTF-8 format, which allows attacker to crash Calls plug-in via sending malformed request.
{
"versions": [
{
"introduced": "10.11.0"
},
{
"fixed": "10.11.7"
},
{
"introduced": "10.12.0"
},
{
"fixed": "10.12.3"
},
{
"introduced": "11.0.0"
},
{
"fixed": "11.0.5"
}
]
}