Description
The package svelte before 3.49.0 is vulnerable to Cross-site Scripting (XSS) due to improper input sanitization and to improper escape of attributes when using objects during SSR (Server-Side Rendering). Exploiting this vulnerability is possible via objects with a custom toString() function.
Recommendation
Update the svelte package to the latest compatible version. Followings are version details:
- Affected version(s): < 3.49.0
- Patched version(s): 3.49.0
References
Could your website be exposed too?
SmartScanner can check your website for Svelte vulnerable to XSS when using objects during server-side rendering and gives you actionable findings to investigate.
Start a free scanRelated Issues
- MCP Inspector is Vulnerable to Potential Command Execution via XSS When Connecting to an Untrusted MCP Server - CVE-2025-58444
- uppy's companion module is vulnerable to Server-Side Request Forgery (SSRF) - CVE-2022-0086
- jQuery UI vulnerable to XSS when refreshing a checkboxradio with an HTML-like initial text label - CVE-2022-31160
- uppy's companion module is vulnerable to Server-Side Request Forgery (SSRF) - uppy - CVE-2022-0086


