CVE-2026-48736

Symfony is a PHP framework for web and console applications and a set of reusable PHP components. From 5.4.0 to 5.4.53, 6.4.41, 7.4.13, and 8.0.13, NoPrivateNetworkHttpClient and IpUtils::PRIVATESUBNETS omitted IPv6 transition prefixes such as 6to4, NAT64, Teredo, and IPv4-compatible IPv6, allowi...

Symfony: IpUtils::PRIVATE_SUBNETS Omits IPv6 Transition Forms (6to4, NAT64, Teredo, IPv4-compatible): SSRF Bypass in NoPrivateNetworkHttpClient

Description Symfony\Component\HttpClient\NoPrivateNetworkHttpClient is documented as a decorator that blocks requests to private networks by default. The list of blocked subnets Symfony\Component\HttpFoundation\IpUtils::PRIVATESUBNETS on 6.4+, a private constant in NoPrivateNetworkHttpClient on 5...