CC: Tweaked is a mod for Minecraft which adds programmable computers, turtles, and more to the game. Prior to version 1.119.0, CC-Tweaked's HTTP API ("http.request", "http.websocket") blocks requests to private network ranges to prevent server-side request forgery (SSRF). This protection can be bypassed on IPv6-capable servers using NAT64 well-known prefix addresses ("64:ff9b::/96"). An attacker who can execute Lua code can reach any internal IPv4 service that the filter is intended to block, by addressing it as "http://[64:ff9b::<ipv4-as-hex>]/" instead of its direct IPv4 address. This affects any CC-Tweaked deployment on a network with NAT64 routing — a configuration that is standard on AWS, GCP, and other cloud platforms when using IPv6-only subnets. Version 1.119.0 fixes the issue.