Jenkins 2.218 and earlier, LTS 2.204.1 and earlier exposed session identifiers on a user's detail object in the whoAmI diagnostic page.
{
"cpes": [
"cpe:2.3:a:jenkins:jenkins:*:*:*:*:lts:*:*:*",
"cpe:2.3:a:jenkins:jenkins:*:*:*:*:-:*:*:*"
],
"severity": "Medium"
}