Summary
@sveltejs/kit has unescaped error message included on error page
The static error.html template for errors contains placeholders that are replaced without escaping the content first.
Details
From https://kit.svelte.dev/docs/errors:
error.html is the page that is rendered when everything else fails. It can contain the following placeholders:
%sveltekit.status%, the HTTP status
%sveltekit.error.message%, the error message
This leads to possible injection if an app explicitly creates an error with a message that contains user controlled content that ends up being something like this inside a server handle function:
error(500, '<script>alert("boom")</script>');
Uncaught errors cannot be exploited like this, as they always render the message "Internal error".
Escaping the message string in the function that creates the html output can be done to improve safety for applications that are using custom errors on the server.
PoC
None provided
Impact
Only applications where user provided input is used in the Error message will be vulnerable, so the vast majority of applications will not be vulnerable
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-2024-53262 has a CVSS score of 4.2 (Low). The vector is network-reachable, low 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 (2.8.3); 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.
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Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
Frequently Asked Questions
- What is CVE-2024-53262? CVE-2024-53262 is a low-severity cross-site scripting (XSS) vulnerability in @sveltejs/kit (npm), affecting versions < 2.8.3. It is fixed in 2.8.3. Untrusted input is rendered as active markup in a victim's browser, which can run script in their session.
- How severe is CVE-2024-53262? CVE-2024-53262 has a CVSS score of 4.2 (Low). 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 @sveltejs/kit are affected by CVE-2024-53262? @sveltejs/kit (npm) versions < 2.8.3 is affected.
- Is there a fix for CVE-2024-53262? Yes. CVE-2024-53262 is fixed in 2.8.3. Upgrade to this version or later.
- Is CVE-2024-53262 exploitable, and should I be worried? Whether CVE-2024-53262 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-2024-53262 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-2024-53262? Upgrade
@sveltejs/kitto 2.8.3 or later.