Mattermost versions 9.5.x <= 9.5.5 and 9.8.0 fail to sanitize the RemoteClusterFrame payloads before audit logging them which allows a high privileged attacker with access to the audit logs to read message contents.
{
"versions": [
{
"introduced": "9.5.0"
},
{
"fixed": "9.5.6"
},
{
"introduced": "0"
},
{
"last_affected": "9.8.0"
}
]
}