CVE-2021-39227

Prototype Pollution in the merge and clone helper methods

Published 17 Sep 2021Modified 17 Jun 2026CWE 1321

In the Trivy database since at least 24 Oct 2026, 07:11 UTCWhen it arrived before that build is not recorded.

Severity by source

NVD9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

GHSA6.2CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Trivy's own label is CRITICAL. Rated critical by NVD. Rated lower by GHSA (medium).

Description

ZRender is a lightweight graphic library providing 2d draw for Apache ECharts. In versions prior to 5.2.1, using `merge` and `clone` helper methods in the `src/core/util.ts` module results in prototype pollution. It affects the popular data visualization library Apache ECharts, which uses and exports these two methods directly. The GitHub Security Advisory page for this vulnerability contains a proof of concept. This issue is patched in ZRender version 5.2.1. One workaround is available: Check if there is `__proto__` in the object keys. Omit it before using it as an parameter in these affected methods. Or in `echarts.util.merge` and `setOption` if project is using ECharts.

Affected packages and fixed versions

Source	Package	Fixed in
npm::GitHub Security Advisory npm	zrender	5.2.1, 4.3.3

References

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