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.
https://github.com/cc-tweaked/CC-Tweaked/security/advisories/GHSA-5jh9-2h63-pw4q
Published: 2026-07-21
Updated: 2026-07-23
Base Score: 6.4
Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:N
Severity: Medium
Base Score: 9.8
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Severity: Critical
Base Score: 7.1
Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:H
Severity: High
EPSS: 0.00054