CVE-2026-27121

svelte performance oriented web framework. 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. This vulnerability is fixed in 5.51.5.

Score
CVSS 3.1 5.4 Medium
Status
Analyzed - security-advisories@github.com
Published
2026-02-20
Last modified
2026-02-23
Weaknesses
CWE-79

Affected products

References

 
 
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