CVE-2026-27902
Svelte: XSS via HTML Comment Injection in SSR Error Boundary Hydration Markers
EPSS 0.03%
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`.
How to fix CVE-2026-27902
To remediate CVE-2026-27902, upgrade the affected package to a fixed version below.
- npm/svelte—upgrade to 5.53.5 or later
Is CVE-2026-27902 being exploited?
Low — EPSS is 0.0%, meaning exploitation activity has not been observed at scale.
Affected packages (1)
- >= 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 |