CVE-2019-13127 is a medium-severity (CVSS 6.1) Improper Input Validation vulnerability in mxgraph. 1 public exploit reference exists, so weaponization risk is real. A fix is available for mxgraph — see the affected versions and patch details below.
mxGraph vulnerable to cross-site scripting in color field
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2019-13127 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,333 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, a proxy for how much of the ecosystem is exposed.
mxgraphnpmDescription
mxGraph through 4.0.0, related to the draw.io Diagrams plugin before 8.3.14 for Confluence and other products, is vulnerable to cross-site scripting. draw.io Diagrams allows the creation and editing of draw.io-based diagrams in Confluence. Among other things, it allows to set the background color of text displayed in the diagram. The color provided by the user is notproperly sanitized, leading to HTML and JavaScript code to be displayed "as it is" to visitors of the page. This allows attackers to execute JavaScript code in the context of the visitor's browser and session and to e.g. run Confluence command under the visitor's user or attack the visitor's browser.
Proof of Concept (PoC):
- Create a new draw.io Diagram, add an element and edit its background color and enter some text to the element
- Enter the following "color":
onMouseOver=alert(1) a= - Save and view the resulting diagram, moving your mouse over the text
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | mxgraph | all versions | 4.0.1npm install mxgraph@4.0.1 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for mxgraph, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update mxgraph to 4.0.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2019-13127 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2019-13127 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2019-13127. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2019-13127 in your dependencies?
O3 Security finds CVE-2019-13127 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.