Summary
XSS Attack with Express API
Workarounds
Don't pass user supplied data directly to res.renderFile.
References
Are there any links users can visit to find out more?
See https://github.com/eta-dev/eta/releases/tag/v2.0.0
Impact
XSS attack - anyone using the Express API is impacted
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-2023-23630 has a CVSS score of 8.6 (High). The vector is network-reachable, 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 (2.0.0); 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.
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See it in your environmentNew to Kodem? Get a demo →Remediation advice
The problem has been resolved. Users should upgrade to version 2.0.0.
Frequently Asked Questions
- What is CVE-2023-23630? CVE-2023-23630 is a high-severity cross-site scripting (XSS) vulnerability in eta (npm), affecting versions < 2.0.0. It is fixed in 2.0.0. Untrusted input is rendered as active markup in a victim's browser, which can run script in their session.
- How severe is CVE-2023-23630? CVE-2023-23630 has a CVSS score of 8.6 (High). 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 eta are affected by CVE-2023-23630? eta (npm) versions < 2.0.0 is affected.
- Is there a fix for CVE-2023-23630? Yes. CVE-2023-23630 is fixed in 2.0.0. Upgrade to this version or later.
- Is CVE-2023-23630 exploitable, and should I be worried? Whether CVE-2023-23630 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-2023-23630 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-2023-23630? Upgrade
etato 2.0.0 or later.