CVE-2020-7746 is a critical-severity (CVSS 9.8) CWE-1321 vulnerability in chart.js. 4 public exploit references exist, so weaponization risk is real. A fix is available for chart.js — see the affected versions and patch details below.
Prototype pollution in chart.js
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2020-7746 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 385,738 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
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.
chart.jsnpmDescription
This affects the package chart.js before 2.9.4. The options parameter is not properly sanitized when it is processed. When the options are processed, the existing options (or the defaults options) are deeply merged with provided options. However, during this operation, the keys of the object being set are not checked, leading to a prototype pollution.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | chart.js | all versions | 2.9.4npm install chart.js@2.9.4 |
Affected Products
chart.jschartjsResearch use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
This affects the package chart.js before 2.9.4. The options parameter is…
This affects the package chart.js before 2.9.4. The options parameter is…
This affects the package chart.js before 2.9.4. The options parameter is…
This affects the package chart.js before 2.9.4. The options parameter is…
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for chart.js, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update chart.js to 2.9.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-7746 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.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
| Product | Fixed in | Advisory |
|---|---|---|
| RHPAM 7.13.1 async | chart.js | RHSA-2022:6813 |
Frequently Asked Questions
Is CVE-2020-7746 in your dependencies?
Find it across npm, including transitive dependencies.