What is CVE-2021-39227?

CVE-2021-39227 is a medium-severity security vulnerability in zrender (npm), affecting versions >= 5.0.0, < 5.2.1. It is fixed in 5.2.1, 4.3.3.

How severe is CVE-2021-39227?

CVE-2021-39227 has a CVSS score of 6.2 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.

Which versions of zrender are affected by CVE-2021-39227?

zrender (npm) versions >= 5.0.0, < 5.2.1 is affected.

Is there a fix for CVE-2021-39227?

Yes. CVE-2021-39227 is fixed in 5.2.1, 4.3.3. Upgrade to this version or later.

Is CVE-2021-39227 exploitable, and should I be worried?

Whether CVE-2021-39227 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk.

What actually determines whether CVE-2021-39227 is exploitable, and how bad it is?

Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.

How do I fix CVE-2021-39227?

Upgrade: zrender to 5.2.1 or later, zrender to 4.3.3 or later.

CVE-2021-39227 in zrender

Q: How severe is CVE-2021-39227?

CVE-2021-39227 has a CVSS score of 6.2 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.

Q: Which versions of zrender are affected by CVE-2021-39227?

zrender (npm) versions >= 5.0.0, < 5.2.1 is affected.

Q: Is there a fix for CVE-2021-39227?

Yes. CVE-2021-39227 is fixed in 5.2.1, 4.3.3. Upgrade to this version or later.

Q: Is CVE-2021-39227 exploitable, and should I be worried?

Whether CVE-2021-39227 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk.

Q: What actually determines whether CVE-2021-39227 is exploitable, and how bad it is?

Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.

Q: How do I fix CVE-2021-39227?

Upgrade: zrender to 5.2.1 or later, zrender to 4.3.3 or later.

Summary

Prototype Pollution in the merge and clone helper methods

References

For more information

Impact

Using merge and clone helper methods in the src/core/util.ts module will have prototype pollution. It will affect the popular data visualization library Apache ECharts, which is using and exported these two methods directly.

CVE-2021-39227 has a CVSS score of 6.2 (Medium). The vector is requires local access, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (5.2.1, 4.3.3); upgrading removes the vulnerable code path.

Affected versions

zrender (>= 5.0.0, < 5.2.1) zrender (<= 4.3.2)

Security releases

zrender → 5.2.1 (npm) zrender → 4.3.3 (npm)

Kodem intelligence

Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.

Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.

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Remediation advice

It has been patched in https://github.com/ecomfe/zrender/pull/826.
Users should update zrender to 5.2.1. and update echarts to 5.2.1 if project is using echarts.

Frequently Asked Questions

What is CVE-2021-39227? CVE-2021-39227 is a medium-severity security vulnerability in zrender (npm), affecting versions >= 5.0.0, < 5.2.1. It is fixed in 5.2.1, 4.3.3.
How severe is CVE-2021-39227? CVE-2021-39227 has a CVSS score of 6.2 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
Which versions of zrender are affected by CVE-2021-39227? zrender (npm) versions >= 5.0.0, < 5.2.1 is affected.
Is there a fix for CVE-2021-39227? Yes. CVE-2021-39227 is fixed in 5.2.1, 4.3.3. Upgrade to this version or later.
Is CVE-2021-39227 exploitable, and should I be worried? Whether CVE-2021-39227 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
What actually determines whether CVE-2021-39227 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
How do I fix CVE-2021-39227?
- Upgrade zrender to 5.2.1 or later
- Upgrade zrender to 4.3.3 or later