Jenkins 2.441 and earlier, LTS 2.426.2 and earlier does not disable a feature of its CLI command parser that replaces an '@' character followed by a file path in an argument with the file's contents, allowing unauthenticated attackers to read arbitrary files on the Jenkins controller file system.
{
"versions": [
{
"introduced": "0"
},
{
"fixed": "2.426.3"
},
{
"introduced": "0"
},
{
"fixed": "2.442"
}
]
}