---
id: "CVE-2026-54589"
page: "https://infrastack.ai/live/CVE-2026-54589"
kind: "vulnerability"
aliases: ["CVE-2026-54589"]
title: "Chartbrew: NAT64 addresses bypass outbound URL guard, reaching internal hosts"
severity: "high"
cvss: 7.0
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["chartbrew", "cloud-metadata", "nat64", "package", "self-hosted"]
not_affected_if: ["ipv4-only", "managed-hosting", "no-nat64-dns64", "version-5.2.1-or-later"]
published_at: "2026-11-06T21:17:09+00:00"
first_seen_at: "2026-11-06T21:45:07+00:00"
updated_at: "2026-11-06T21:46:42+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-54589", "first_seen_at": "2026-11-06T21:45:07+00:00"}]
exploit_sources: []
---

# Chartbrew: NAT64 addresses bypass outbound URL guard, reaching internal hosts

Link for people: https://infrastack.ai/live/CVE-2026-54589 (this .md is for agents)

Chartbrew's outbound URL check did not recognize IPv4 addresses embedded in NAT64 IPv6 prefixes, so a user who can create API connections can point requests at private IPv4 hosts. The attacker can read responses from cloud metadata endpoints and internal hosts reachable through the NAT64 gateway.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check the Chartbrew version in use; versions before `5.2.1` are affected.
- Confirm whether the deployment runs on a NAT64/DNS64 network path; IPv4-only deployments are not affected by this bypass.
- Check who holds permission to create or edit API data connections.

## Fix

- Chartbrew: upgrade to `5.2.1`.

## Timeline

- 2026-11-06T21:45:07+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-54589

## Documents

- [advisory] Vendor advisory: github.com https://github.com/chartbrew/chartbrew/security/advisories/GHSA-6m7q-jmp7-3vw8
- [fix] Patch: github.com https://github.com/chartbrew/chartbrew/commit/8cfac8076bb0001b1571d93ef923698f53767751
- [fix] Release notes: github.com https://github.com/chartbrew/chartbrew/releases/tag/v5.2.1

## From the sources

Chartbrew is an open-source web application that can connect directly to databases and APIs and use the data to create charts. Prior to 5.2.1, the outbound URL guard recognized ordinary IPv4, IPv6, and IPv4-mapped IPv6 destinations but did not recognize IPv4 addresses embedded in NAT64 prefixes. The vulnerable surface is aPI Data Connection outbound requests routed through server/modules/outboundTargetPolicy.js. An authenticated user with permission to create or edit an API connection supplies an attacker-controlled hostname or redirect whose DNS answer is a NAT64 address embedding a private or link-local IPv4 destination. The policy treated the NAT64 address as public; a NAT64 gateway then translated it to the embedded private IPv4 address after validation. The bypass requires a NAT64/DNS64 deployment path and connection-management privileges. IPv4-only deployments are not affected by this specific bypass. The attacker can read responses from 169.254.169.254 cloud metadata and arbitrary internal IPv4 hosts and ports reachable through the NAT64 gateway. This issue is fixed in version 5.2.1.

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