CVE-2026-42573
MediumCVSS 6.1Exploitation Probability (EPSS)
Low risk24th percentile - higher than 24% of all known CVEs
Summary
Svelte prior to version 5.55.7 is vulnerable to DOM clobbering of its internal framework state on elements, potentially leading to XSS attacks.
Risk Assessment
An attacker can inject a malicious script that executes in the victim's browser, stealing data or hijacking the session.
Recommendation
Update Svelte to version 5.55.7 or later.
Other vulnerabilities in Svelte
See all- CVE-2026-42599Medium
Svelte prior to version 5.55.7 contains a vulnerability where, when using spread syntax to render attributes from untrusted data, event handlers are included in the rendered HTML output. If an application spreads user-controlled data as element attributes, an attacker can inject malicious event handlers that execute in victims' browsers. The vulnerability only triggers if the user's browser has JavaScript enabled and Svelte's hydration mechanism does not reach the vulnerable element before the event fires.
- CVE-2026-42567High
Svelte framework versions 5.51.5 through 5.55.6 have a ReDoS vulnerability in <svelte:element this={tag}></svelte:element>. An internal regex can take exponential time to test.
Original NVD description (English source)
Svelte is a performance oriented web framework. Prior to version 5.55.7, Svelte was vulnerable to DOM clobbering of its internal framework state on elements, potentially leading to XSS attacks. This issue has been patched in version 5.55.7.