draw.io: Unauthenticated SSRF via IPv6 ULA blocklist bypass in /embed2.js
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- Information disclosure
- Confidentiality · integrity · availability
- Low · None · None
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-918 and the CVSS impact.
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 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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
- Fix · CNA drawio (jgraph) Fixed in 30.3.8
Timeline
- 2026-10-02 Threatist record created from CVE-2026-76898
References
More jgraph vulnerabilities
- TI-2023-03691 OS Command Injection in jgraph/drawio CVSS 3.1CRITICAL 9.8
- TI-2023-03690 OS Command Injection in jgraph/drawio CVSS 3.1CRITICAL 9.8
- TI-2023-03178 Denial of Service in jgraph/drawio CVSS 3.1HIGH 7.5
- TI-2026-83372 Search path hijacking in draw.io Desktop on Windows CVSS 3.1HIGH 7.8
- TI-2023-02834 Cross-site Scripting (XSS) - Stored in jgraph/drawio CVSS 3.1MEDIUM 6.1
- TI-2022-03550 Cross-site Scripting (XSS) - DOM in jgraph/drawio CVSS 3.1MEDIUM 6.1
Sources
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences