CVE-2021-23444 is a critical-severity (CVSS 9.8) CWE-843 vulnerability in jointjs. 3 public exploit references exist, so weaponization risk is real. A fix is available for jointjs — see the affected versions and patch details below.
Prototype Pollution in jointjs
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2021-23444 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 385,386 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, a proxy for how much of the ecosystem is exposed.
jointjsnpmDescription
This affects the package jointjs before 3.4.2. A type confusion vulnerability can lead to a bypass of CVE-2020-28480 when the user-provided keys used in the path parameter are arrays in the setByPath function.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | jointjs | all versions | 3.4.2npm install jointjs@3.4.2 |
Affected Products
jointjsclientResearch 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 jointjs, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update jointjs to 3.4.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-23444 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.
Frequently Asked Questions
Is CVE-2021-23444 in your dependencies?
Find it across npm, including transitive dependencies.