An issue was discovered in MediaWiki before 1.35.12, 1.36.x through 1.39.x before 1.39.5, and 1.40.x before 1.40.1. There is XSS in youhavenewmessagesmanyusers and youhavenewmessages i18n messages. This is related to MediaWiki:Youhavenewmessagesfromusers.
{
"versions": [
{
"introduced": "0"
},
{
"fixed": "1.35.12"
},
{
"introduced": "1.39.0"
},
{
"fixed": "1.39.5"
},
{
"introduced": "0"
},
{
"last_affected": "1.40.0-NA"
}
]
}