GHSA-qgvg-pr8v-6rr3

Svelte: XSS via HTML Comment Injection in SSR Error Boundary Hydration Markers

Source: GitHub Advisory Database (reviewed) Moderate CVE-2026-27902

Packages

Ecosystem	Package	Affected	Fixed in
npm	svelte	>= 5.53.0, < 5.53.5	5.53.5

Details

As written in the advisory (Markdown source, shown as plain text).

Errors from `transformError` were not correctly escaped prior to being embedded in the HTML output, causing potential HTML injection and XSS if attacker-controlled content is returned from `transformError`.

References

External links from the advisory. They lead to third-party sites.

https://github.com/sveltejs/svelte/security/advisories/GHSA-qgvg-pr8v-6rr3 web
https://nvd.nist.gov/vuln/detail/CVE-2026-27902 advisory
https://github.com/sveltejs/svelte/commit/0298e979371bb583855c9810db79a70a551d22b9 web
https://github.com/sveltejs/svelte package
https://github.com/sveltejs/svelte/releases/tag/[email protected] web