GHSA-m64q-4jqh-f72f is a medium-severity (CVSS 6.1) Cross-site Scripting (XSS) vulnerability in @excalidraw/excalidraw. A fix is available for @excalidraw/excalidraw — see the affected versions and patch details below.
Stored Cross-site Scripting (XSS) in excalidraw's web embed component
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
Exploitation and automatability from CISA’s SSVC triage for GHSA-m64q-4jqh-f72f.
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
GHSA-m64q-4jqh-f72f 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, and reverse-dependency count shows how many other packages break if it stays unpatched.
@excalidraw/excalidrawnpmDescription
Summary
A stored XSS vulnerability in Excalidraw's web embeddable component. This allows arbitrary JavaScript to be run in the context of the domain where the editor is hosted.
Poc
Inserting an embed with the below url (can be copy/pasted onto canvas to insert as embed) will log 42 to the console:
https://gist.github.com/vv=v<script>console.log(42)</script>
Details
There were two vectors. One rendering untrusted string as iframe's srcdoc without properly sanitizing against HTML injection. Second by improperly sanitizing against attribute HTML injection. This in conjunction with allowing allow-same-origin sandbox flag (necessary for several embeds) resulted in the XSS.
Former was fixed by no longer rendering unsafe srcdoc content verbatim, and instead strictly parsing the supplied content and constructing the srcdoc manually. The latter by sanitizing properly.
The allow-same-origin flag is now also set only in cases that require it, following the principle of least privilege.
Impact
This is a cross site scripting vulnerability, for more information, please see: https://portswigger.net/web-security/cross-site-scripting
Two npm @excalidraw/excalidraw stable version releases were affected (0.16.x, 0.17.x), and both are now patched.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @excalidraw/excalidraw | ≥ 0.16.0&&< 0.16.4 | 0.16.4npm install @excalidraw/excalidraw@0.16.4 |
| 📦npm | @excalidraw/excalidraw | ≥ 0.17.0&&< 0.17.6 | 0.17.6npm install @excalidraw/excalidraw@0.17.6 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @excalidraw/excalidraw, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update @excalidraw/excalidraw to 0.16.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-m64q-4jqh-f72f 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 GHSA-m64q-4jqh-f72f can be triaged on real exposure rather than presence alone.
Tailored to GHSA-m64q-4jqh-f72f. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-m64q-4jqh-f72f in your dependencies?
O3 Security finds GHSA-m64q-4jqh-f72f across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.