CVE-2026-76898
CVE-2026-76898 — draw.io: Unauthenticated SSRF via IPv6 ULA blocklist bypass in /embed2.js
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…
Published Updated Sources: cvelistV5, GitHub_M
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the scoring sources call it.
Exploitation
Unreported
no source claims exploitation
EPSS
0%
chance of exploitation in 30 days
CVSS base
7.7
HIGH
CISA SSVC assessment
Three decision points CISA publishes for the CVEs it assesses · SSVC 2.0.3. A stakeholder decision, not a severity score.
Exploitation
PoC
none · proof-of-concept · active
Automatable
Yes
can an attacker script all four kill-chain steps
Technical impact
Partial
partial · total control of the vulnerable component
Affected scope
The catalog records vendors and products as separate lists, not pairs, so which product belongs to which vendor is not something this page can say.
Vendors (1)
Products (1)
Every base score collected
Sources score independently and disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Source |
|---|---|---|---|---|---|
| 7.7 | CVSS 4.0 | HIGH | — | — | cvelistV5 |
Weakness & attack patterns
- CWE-918
Detection
Read off the CVSS vector and the weakness class. Starting points, not rules we have tested.
- Search application, proxy, and WAF logs for requests touching /main/java/com/mxgraph/online/Utils.java, /7, /32, /embed2.js?fetch=, /main/java/com/mxgraph/online/EmbedServlet2.java, /embed2.js.
References
3 on the record
- github.com/jgraph/drawio/security/advisories/GHSA-m3q9-cwfq-hcjc
x_refsource_CONFIRM
- github.com/jgraph/drawio/commit/73c4a91196246bbdb60f52b15871e82006b7972d
x_refsource_MISC
- github.com/jgraph/drawio/releases/tag/v30.3.8
x_refsource_MISC
Elsewhere on this site
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.