Summary
"Unsanitized input from the request URL flows into end, where it is used to render an HTML page returned to the user. This may result in a Cross-Site Scripting attack (XSS)."
Details
Source of potentially tainted data is in packages/kit/src/exports/vite/dev/index.js, line 437. This potentially tainted data is passed through a number of steps (which I could detail if you'd like) all the way down to line 91 in packages/kit/src/exports/vite/utils.js, which performs an operation that Snyk believes an attacker shouldn't be allowed to manipulate.
Another source of potentially tainted data (according to Snyk) comes from packages/kit/src/exports/vite/utils.js, line 30, col 30 (i.e., the url property of req). This potentially tainted data is passed through a number of steps (which I could detail if you'd like) all the way down line 91 in packages/kit/src/exports/vite/utils.js, which performs an operation that Snyk believes an attacker shouldn't be allowed to manipulate.
PoC
Not provided
Impact
Little to none. The Vite development is not exposed to the network by default. And even if someone were able to trick a developer into executing an XSS against themselves, a development database should not have any sensitive data.
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.
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-2024-53261? CVE-2024-53261 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.
- Which versions of @sveltejs/kit are affected by CVE-2024-53261? @sveltejs/kit (npm) versions < 2.8.3 is affected.
- Is there a fix for CVE-2024-53261? Yes. CVE-2024-53261 is fixed in 2.8.3. Upgrade to this version or later.
- Is CVE-2024-53261 exploitable, and should I be worried? Whether CVE-2024-53261 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-2024-53261 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-2024-53261? Upgrade
@sveltejs/kitto 2.8.3 or later.