CVE-2026-27902
EPSS 0.03%Svelte: XSS via HTML Comment Injection in SSR Error Boundary Hydration Markers
Published: 2/26/2026Modified: 2/26/2026
Also known as:GHSA-qgvg-pr8v-6rr3
Description
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`.
Affected packages (1)
- npm/svelte>= 5.53.0, < 5.53.5
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 4.0 | — | CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:P/VC:L/VI:N/VA:N/SC:H/SI:H/SA:N |
References (5)
- ADVISORYhttps://nvd.nist.gov/vuln/detail/CVE-2026-27902
- PATCHhttps://github.com/sveltejs/svelte
- WEBhttps://github.com/sveltejs/svelte/commit/0298e979371bb583855c9810db79a70a551d22b9
- WEBhttps://github.com/sveltejs/svelte/releases/tag/[email protected]
- WEBhttps://github.com/sveltejs/svelte/security/advisories/GHSA-qgvg-pr8v-6rr3