PT-2026-3102 · Svelte · Svelte

Camilo Vera · Published 2026-01-15 · Updated 2026-01-15 · CVE-2025-15265

Positive Technologies (AI Summary)

CVSS v3.1

6.1

Medium

Base vector

AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Name of the Vulnerable Software and Affected Versions Svelte versions 5.46.0 through 5.46.2

Description A cross-site scripting (XSS) issue exists due to improper escaping of hydratable keys. When these keys include untrusted user input, arbitrary JavaScript can be injected into server-rendered HTML. This allows for remote script execution in users' browsers, potentially leading to session theft and account compromise. The hydratable function uses a key to uniquely identify data, and this key is embedded into a <script> block without proper escaping. A malicious key can terminate the script and inject arbitrary JavaScript into the HTML response.

Recommendations Upgrade to a patched version of Svelte.

Exploit

Fix

XSS

Weakness Enumeration

CWE-79

Related Identifiers

CVE-2025-15265

GHSA-6738-R8G5-QWP3

Affected Products

Svelte

References · 9

• 🔥 https://fluidattacks.com/advisories/lydian · Exploit
• https://github.com/sveltejs/svelte/security/advisories/GHSA-6738-r8g5-qwp3 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2025-15265 · Security Note
• https://osv.dev/vulnerability/GHSA-6738-r8g5-qwp3 · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2025-15265 · Vendor Advisory
• https://github.com/sveltejs/svelte · Note
• https://github.com/sveltejs/svelte/releases/tag/svelte%405.46.4 · Note
• https://github.com/sveltejs/svelte/commit/ef81048e238844b729942441541d6dcfe6c8ccca · Note
• https://twitter.com/CVEnew/status/2011926057956622830 · Twitter Post