GitHub Advisoryadvisory · npm

GHSA-qgvg-pr8v-6rr3 Svelte: XSS via HTML Comment Injection in SSR Error Boundary Hydration Markers

MEDIUM Published 2026-02-26 Modified 2026-02-26 Official page ↗
Aliases
CVE-2026-27902
Ecosystem
npm
Packages
svelte
Severity
Moderate
CVSS vector
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
Weaknesses
CWE-79
Reviewed
2026-02-26

Affected packages

• npm svelte: >= 5.53.0, < 5.53.5 → fixed in 5.53.5

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`.

Related

Alias · CVE (1)

  • CVE-2026-27902 Svelte performance oriented web framework. vulnerability

Weakness · CWE (1)

  • CWE-79 Improper Neutralization of Input During Web Page Generation weakness

References