In Jenkins 2.499 and earlier, LTS 2.492.1 and earlier, redirects starting with backslash (\) characters are considered safe, allowing attackers to perform phishing attacks by having users go to a Jenkins URL that will forward them to a different site, because browsers interpret these characters as part of scheme-relative redirects.
{
"severity": "Medium",
"cpes": [
"cpe:2.3:a:jenkins:jenkins:*:*:*:*:*:maven:*:*"
]
}