GHSA-pr6f-5x2q-rwfp
Svelte SSR vulnerable to cross-site scripting via spread attributes
Packages
Details
As written in the advisory (Markdown source, shown as plain text).
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. Note that this vulnerability _only_ triggers if the user's browser has JavaScript enabled but Svelte's hydration mechanism does not reach the vulnerable element before the event fires.
This is similar to but different from [CVE-2026-27121](https://nvd.nist.gov/vuln/detail/CVE-2026-27121).
References
External links from the advisory. They lead to third-party sites.