CVE-2025-15265: Svelte

Medium severity, CVSS 6.1. EPSS: 0.4% chance of exploitation in the next 30 days.

An SSR XSS exists in async hydration when attacker‑controlled keys are passed to hydratable. The key is embedded inside a <script> block without HTML‑safe escaping, allowing </script> to terminate the script and inject arbitrary JavaScript. This enables remote script execution in users' browsers, with potential for session theft and account compromise. This issue affects Svelte: from 5.46.0 before 5.46.3.

Affected products

• Svelte Svelte: from 5.46.0, before 5.46.3 (fixed in 5.46.3)

Published 2026-01-15. Last modified 2026-06-17.