Summary
Svelecte item names vulnerable to execution of arbitrary JavaScript
Svelecte item names are rendered as raw HTML with no escaping. This allows the injection of arbitrary HTML into the Svelecte dropdown. This can be exploited to execute arbitrary JavaScript whenever a Svelecte dropdown is opened.
Details
Item names given to Svelecte appear to be directly rendered as HTML by the default item renderer. This means that any HTML tags in the name are rendered as HTML elements not as text.
Note that the custom item renderer shown in https://mskocik.github.io/svelecte/#item-rendering is also vulnerable to the same exploit.
To prevent this all special HTML characters in item names should be escaped (for example using document.createTextNode()).
PoC
<script>
import Svelecte from 'svelecte';
const list = [
{ id: 1, name: `Item 1` },
{ id: 2, name: `Item 2<img style="display:none;" src=1 onerror="alert('JavaScript executed!');"/>` },
{ id: 3, name: 'Item 3'}
];
</script>
<Svelecte options={list}></Svelecte>
This code snippet demonstrates how the vulnerability can be used to execute arbitrary JavaScript without the user's knowledge when the Svelecte dropdown is opened (note that visually item 2 appears identical to other items).
In this case the script is hardcoded, but in practice the real danger is that some applications may use Svelecte with items that are created by users or come from low-trust sources where someone else could add a malicious script to the item name.
Impact
Any site that uses Svelecte with dynamically created items either from an external source or from user-created content could be vulnerable to an XSS attack (execution of untrusted JavaScript), clickjacking or any other attack that can be performed with arbitrary HTML injection.
The actual impact of this vulnerability for a specific application depends on how trustworthy the sources that provide Svelecte items are and the steps that the application has taken to mitigate XSS attacks. XSS attacks using this vulnerability are mostly mitigated by a Content Security Policy that blocks inline JavaScript.
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-2023-38687 has a CVSS score of 5.4 (Medium). The vector is network-reachable, low 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 (3.16.3); 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.
Already deployed Kodem?
See it in your environmentNew to Kodem? Get a demo →Remediation advice
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
Frequently Asked Questions
- What is CVE-2023-38687? CVE-2023-38687 is a medium-severity cross-site scripting (XSS) vulnerability in svelecte (npm), affecting versions < 3.16.3. It is fixed in 3.16.3. Untrusted input is rendered as active markup in a victim's browser, which can run script in their session.
- How severe is CVE-2023-38687? CVE-2023-38687 has a CVSS score of 5.4 (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 svelecte are affected by CVE-2023-38687? svelecte (npm) versions < 3.16.3 is affected.
- Is there a fix for CVE-2023-38687? Yes. CVE-2023-38687 is fixed in 3.16.3. Upgrade to this version or later.
- Is CVE-2023-38687 exploitable, and should I be worried? Whether CVE-2023-38687 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-2023-38687 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-2023-38687? Upgrade
svelecteto 3.16.3 or later.