PT-2026-47875 · Sveltejs · Svelte

Published 2026-06-09 · Updated 2026-06-09 · CVE-2026-42599

NVD

CVSS v4.0

5.1

Medium

Base vector

AV:N/AC:H/AT:P/PR:H/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Svelte is a performance oriented web framework. Prior to version 5.55.7, when using spread syntax to render attributes from untrusted data, event handler properties are included in the rendered HTML output. If an application spreads user-controlled or external data as element attributes, an attacker can inject malicious event handlers that execute in victims' browsers. Note that this vulnerability only triggers if the user's browser has JavaScript enabled but Svelte's hydration mechanism does not reach the vulnerable element before the event fires. This issue has been patched in version 5.55.7.

Fix

XSS

Weakness Enumeration

CWE-79

Related Identifiers

CVE-2026-42599

Affected Products

Svelte

References · 3

• https://nvd.nist.gov/vuln/detail/CVE-2026-42599 · Security Note
• https://github.com/sveltejs/svelte/releases/tag/svelte%405.55.7 · Note
• https://github.com/sveltejs/svelte/security/advisories/GHSA-pr6f-5x2q-rwfp · Note