Summary
A cross-site scripting (XSS) vulnerability exists in Apache ECharts in the Lines series tooltip rendering logic.
This issue affects Apache ECharts: from before 6.1.0.
In versions prior to 6.1.0, if both Lines series and tooltip are used, and no user-specified tooltip.formatter is provided, and series.data[i].name is specified, raw HTML string series.data[i].name can be rendered through innerHTML sink into tooltip content. Although tooltip is allowed to accept user-provided raw HTML via a custom tooltip.formatter, the built-in tooltip formatters conventionally perform HTML escaping automatically. This case breaks that convention and may unexpectedly lead to script execution when tooltips are displayed.
Users are recommended to upgrade to version 6.1.0 if using the Lines series in this way, which fixes the issue.
Impact
Untrusted input is rendered as active markup in a victim's browser, which can run script in their session. Typical impact: session or credential theft, and actions taken as the user.
CVE-2026-45249 has a CVSS score of 6.1 (Medium). The vector is network-reachable, no privileges required, and user interaction required. 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 (6.1.0); upgrading removes the vulnerable code path.
Affected versions
Security releases
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.
Remediation advice
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
Frequently Asked Questions
- What is CVE-2026-45249? CVE-2026-45249 is a medium-severity cross-site scripting (XSS) vulnerability in echarts (npm), affecting versions < 6.1.0. It is fixed in 6.1.0. Untrusted input is rendered as active markup in a victim's browser, which can run script in their session.
- How severe is CVE-2026-45249? CVE-2026-45249 has a CVSS score of 6.1 (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 echarts are affected by CVE-2026-45249? echarts (npm) versions < 6.1.0 is affected.
- Is there a fix for CVE-2026-45249? Yes. CVE-2026-45249 is fixed in 6.1.0. Upgrade to this version or later.
- Is CVE-2026-45249 exploitable, and should I be worried? Whether CVE-2026-45249 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-2026-45249 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-2026-45249? Upgrade
echartsto 6.1.0 or later.