There is a denial of service vulnerability in the header parsing component of Rack.
{
"availability": "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro",
"binaries": [
{
"binary_version": "1.5.2-3+deb8u3ubuntu1~esm7",
"binary_name": "librack-ruby"
},
{
"binary_version": "1.5.2-3+deb8u3ubuntu1~esm7",
"binary_name": "librack-ruby1.8"
},
{
"binary_version": "1.5.2-3+deb8u3ubuntu1~esm7",
"binary_name": "librack-ruby1.9.1"
},
{
"binary_version": "1.5.2-3+deb8u3ubuntu1~esm7",
"binary_name": "ruby-rack"
}
]
}