In Jenkins 2.196 and earlier, LTS 2.176.3 and earlier, the f:expandableTextBox form control interpreted its content as HTML when expanded, resulting in a stored XSS vulnerability exploitable by users with permission to define its contents (typically Job/Configure).
{
"versions": [
{
"introduced": "0"
},
{
"last_affected": "2.176.3"
},
{
"introduced": "0"
},
{
"last_affected": "2.196"
}
]
}