Jenkins 2.196 and earlier, LTS 2.176.3 and earlier printed the value of the "Cookie" HTTP request header on the /whoAmI/ URL, allowing attackers exploiting another XSS vulnerability to obtain the HTTP session cookie despite it being marked HttpOnly.
{
"versions": [
{
"introduced": "0"
},
{
"last_affected": "2.176.3"
},
{
"introduced": "0"
},
{
"last_affected": "2.196"
}
]
}