sveltejs/svelte · Security
Svelte affected by cross-site scripting via spread attributes in Svelte SSR
- GHSA ID
- GHSA-f7gr-6p89-r883
- CVE ID
- CVE-2026-27121
- Severity
- medium
- Published
- Updated
- CVSS v4
- 5.1 · CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:N/VC:L/VI:N/VA:N/SC:H/SI:H/SA:N
Description
Versions of svelte prior to 5.51.5 are vulnerable to cross-site scripting (XSS) during server-side rendering. When using spread syntax to render attributes from untrusted data, event handler properties are included in the rendered HTML output. If an application spreads user-controlled or external data as element attributes, an attacker can inject malicious event handlers that execute in victims' browsers.
CWEs
- CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')