In Jenkins 2.399 and earlier, LTS 2.387.3 and earlier, POST requests are sent in order to load the list of context actions. If part of the URL includes insufficiently escaped user-provided values, a victim may be tricked into sending a POST request to an unexpected endpoint by opening a context menu.
{
"versions": [
{
"introduced": "0"
},
{
"fixed": "2.400"
},
{
"introduced": "0"
},
{
"fixed": "2.401.1"
}
]
}