What is CVE-2018-6341?

CVE-2018-6341 is a medium-severity cross-site scripting (XSS) vulnerability in react-dom (npm), affecting versions = 16.0.0. It is fixed in 16.0.1, 16.1.2, 16.2.1, 16.3.3, 16.4.2. Untrusted input is rendered as active markup in a victim's browser, which can run script in their session.

How severe is CVE-2018-6341?

CVE-2018-6341 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 react-dom are affected by CVE-2018-6341?

react-dom (npm) versions = 16.0.0 is affected.

Is there a fix for CVE-2018-6341?

Yes. CVE-2018-6341 is fixed in 16.0.1, 16.1.2, 16.2.1, 16.3.3, 16.4.2. Upgrade to this version or later.

Is CVE-2018-6341 exploitable, and should I be worried?

Whether CVE-2018-6341 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-2018-6341 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-2018-6341?

Upgrade: react-dom to 16.0.1 or later, react-dom to 16.1.2 or later, react-dom to 16.2.1 or later, react-dom to 16.3.3 or later, react-dom to 16.4.2 or later.

CVE-2018-6341 in react-dom

Summary

Cross-Site Scripting in react-dom

Affected versions of react-dom are vulnerable to Cross-Site Scripting (XSS). The package fails to validate attribute names in HTML tags which may lead to Cross-Site Scripting in specific scenarios. This may allow attackers to execute arbitrary JavaScript in the victim's browser. To be affected by this vulnerability, the application needs to:

be a server-side React app
be rendered to HTML using ReactDOMServer
include an attribute name from user input in an HTML tag

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-2018-6341 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 (16.0.1, 16.1.2, 16.2.1, 16.3.3, 16.4.2); upgrading removes the vulnerable code path.

Affected versions

react-dom (= 16.0.0) react-dom (>= 16.1.0, < 16.1.2) react-dom (= 16.2.0) react-dom (>= 16.3.0, < 16.3.3) react-dom (>= 16.4.0, < 16.4.2)

Security releases

react-dom → 16.0.1 (npm) react-dom → 16.1.2 (npm) react-dom → 16.2.1 (npm) react-dom → 16.3.3 (npm) react-dom → 16.4.2 (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

If you are using react-dom 16.0.x, upgrade to 16.0.1 or later.
If you are using react-dom 16.1.x, upgrade to 16.1.2 or later.
If you are using react-dom 16.2.x, upgrade to 16.2.1 or later.
If you are using react-dom 16.3.x, upgrade to 16.3.3 or later.
If you are using react-dom 16.4.x, upgrade to 16.4.2 or later.

Frequently Asked Questions

What is CVE-2018-6341? CVE-2018-6341 is a medium-severity cross-site scripting (XSS) vulnerability in react-dom (npm), affecting versions = 16.0.0. It is fixed in 16.0.1, 16.1.2, 16.2.1, 16.3.3, 16.4.2. Untrusted input is rendered as active markup in a victim's browser, which can run script in their session.
How severe is CVE-2018-6341? CVE-2018-6341 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 react-dom are affected by CVE-2018-6341? react-dom (npm) versions = 16.0.0 is affected.
Is there a fix for CVE-2018-6341? Yes. CVE-2018-6341 is fixed in 16.0.1, 16.1.2, 16.2.1, 16.3.3, 16.4.2. Upgrade to this version or later.
Is CVE-2018-6341 exploitable, and should I be worried? Whether CVE-2018-6341 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-2018-6341 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-2018-6341?
- Upgrade react-dom to 16.0.1 or later
- Upgrade react-dom to 16.1.2 or later
- Upgrade react-dom to 16.2.1 or later
- Upgrade react-dom to 16.3.3 or later
- Upgrade react-dom to 16.4.2 or later