{"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","slug":"CVE-2026-76898","body":"## Overview\n\ndraw.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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":42,"depthScoreParts":{"impact":42.4,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}