Description
svelte performance oriented web framework. A potential mXSS vulnerability exists in Svelte for versions up to but not including 4.2.19. Svelte improperly escapes HTML on server-side rendering. The assumption is that attributes will always stay as such, but in some situation the final DOM tree rendered on browsers is different from what Svelte expects on server-side rendering. This may be leveraged to perform XSS attacks, and a type of the XSS is known as mXSS (mutation XSS). More specifically, this can occur when injecting malicious content into an attribute within a `noscript` tag. This issue has been addressed in release version 4.2.19. Users are advised to upgrade. There are no known workarounds for this vulnerability.
CVSS breakdown
CVSS 3.1
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
None
Affected products
- sveltejs / svelte< 4.2.19 – < 4.2.19