CVE-2026-27902
Svelte Vulnerable to XSS via HTML Comment Injection in SSR Error Boundary Hydration Markers
- State
- Published
- Severity
- 5.3 Medium
- Published
- Feb 26, 2026
- Updated
- Feb 26, 2026
- Reserved
- Feb 24, 2026
Description
Svelte performance oriented web framework. Prior to version 5.53.5, 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`. Version 5.53.5 fixes the issue.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 5.3 Medium | 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 | GitHub_M |
Weaknesses
- CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Affected Products
| Product | Versions |
|---|---|
sveltesveltejs |
|
References
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