CVE-2021-29489
MEDIUMCVE-2021-29489 is a medium-severity (CVSS 5.4) Cross-site Scripting (XSS) vulnerability in highcharts. O3 Security confirms whether CVE-2021-29489 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Options structure open to Cross-site Scripting if passed unfiltered
Real-World Exposure
highchartsReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects npm packages — download data is not available via public APIs for these ecosystems.
Description
Highcharts JS is a JavaScript charting library based on SVG. In Highcharts versions 8 and earlier, the chart options structure was not systematically filtered for XSS vectors. The potential impact was that content from untrusted sources could execute code in the end user's browser. The vulnerability is patched in version 9. As a workaround, implementers who are not able to upgrade may apply DOMPurify recursively to the options structure to filter out malicious markup.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | highcharts | all versions | 9.0.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for highcharts. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update highcharts to 9.0.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-29489 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 pinpoints whether CVE-2021-29489 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2021-29489. 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-2021-29489 in your dependencies?
O3 detects CVE-2021-29489 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.