CVE-2026-42599

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.

CVSS v3 6.1 MEDIUM

6.1^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.8 / Impact : 2.7

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction REQUIRED

Confidentiality Impact LOW

Integrity Impact LOW

Availability Impact NONE

Scope CHANGED

References

Link	Resource
https://github.com/sveltejs/svelte/releases/tag/svelte%405.55.7	Release Notes
https://github.com/sveltejs/svelte/security/advisories/GHSA-pr6f-5x2q-rwfp	Vendor Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:svelte:svelte:*:*:*:*:*:node.js:*:*

History

11 Jun 2026, 18:41

Type	Values Removed	Values Added
References	~~() https://github.com/sveltejs/svelte/releases/tag/svelte%405.55.7 -~~	() https://github.com/sveltejs/svelte/releases/tag/svelte%405.55.7 - Release Notes
References	~~() https://github.com/sveltejs/svelte/security/advisories/GHSA-pr6f-5x2q-rwfp -~~	() https://github.com/sveltejs/svelte/security/advisories/GHSA-pr6f-5x2q-rwfp - Vendor Advisory
First Time		Svelte svelte Svelte
CVSS	v2 : ~~unknown~~ v3 : ~~unknown~~	v2 : unknown v3 : 6.1
CPE		cpe:2.3:a:svelte:svelte::::::node.js::*

09 Jun 2026, 17:17

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-06-09 17:17

Updated : 2026-06-11 18:41

NVD link : CVE-2026-42599

Mitre link : CVE-2026-42599

CVE.ORG link : CVE-2026-42599

JSON object : View

Products Affected

svelte

svelte

CWE

CWE-79

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

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