symfony/http-client is a module for the Symphony PHP framework which provides powerful methods to fetch HTTP resources synchronously or asynchronously. When using the NoPrivateNetworkHttpClient, some internal information is still leaking during host resolution, which leads to possible IP/port enumeration. As of versions 5.4.46, 6.4.14, and 7.1.7 the NoPrivateNetworkHttpClient now filters blocked IPs earlier to prevent such leaks. All users are advised to upgrade. There are no known workarounds for this vulnerability.