---
id: CVE-2026-76898
title: draw.io is a configurable diagramming and whiteboarding application
summary: >-
  draw.io is a configurable diagramming and whiteboarding application. Prior to
  version 30.3.8, src/main/java/com/mxgraph/online/Utils.java checks IPv6 Unique
  Local Addresses in Utils.sanitizeUrl() by comparing the text prefixes fc00::
  and…
severity: high
cvss: 7.7
cvssVector: 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:H/SI:N/SA:N'
cwe:
  - CWE-918
vendor: jgraph
product: drawio
affected:
  - drawio < 30.3.8
published: '2026-09-21'
updated: '2026-09-21'
sourceUpdated: '2026-09-21T17:18:50.350'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-76898'
references:
  - url: >-
      https://github.com/jgraph/drawio/commit/73c4a91196246bbdb60f52b15871e82006b7972d
    label: security-advisories@github.com
  - url: 'https://github.com/jgraph/drawio/releases/tag/v30.3.8'
    label: security-advisories@github.com
  - url: 'https://github.com/jgraph/drawio/security/advisories/GHSA-m3q9-cwfq-hcjc'
    label: security-advisories@github.com
tags:
  - nvd
  - cve.org
cvssSource: cna
ingestedAt: '2026-09-21T16:49:07.868Z'
---

## Overview

draw.io is a configurable diagramming and whiteboarding application. Prior to version 30.3.8, src/main/java/com/mxgraph/online/Utils.java checks IPv6 Unique Local Addresses in Utils.sanitizeUrl() by comparing the text prefixes fc00:: and fd00::, but the JDK returns the expanded address form, so the fc00::/7 range, including the AWS metadata range fd00:ec2::/32, is not blocked. An unauthenticated request to /embed2.js?fetch= can therefore make src/main/java/com/mxgraph/online/EmbedServlet2.java fetch an IPv6 ULA internal resource and reflect the response to the requester. Utils.validatedAddress() uses the same private-address check for the separate ProxyServlet path, which requires ENABLE_DRAWIO_PROXY=1. The primary /embed2.js path requires no proxy feature flag or DNS rebinding, and it can disclose cloud metadata credentials or data from other IPv6-reachable internal services. This issue is fixed in version 30.3.8.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.