What’s Vulnerable › Vulnerabilities

CVE-2026-42573: Svelte: XSS via DOM Clobbering of Internal Framework State

• Severity: medium (CVSS 6.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-06-09 · updated 2026-07-23
• Weakness: CWE-79

Description

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.

Affected products

• sveltejs svelte: before 5.55.7 — fixed in 5.55.7

How to fix

Upgrade to a fixed version: sveltejs svelte 5.55.7. Check the vendor advisory for mitigations.

References

• https://github.com/sveltejs/svelte/releases/tag/svelte%405.55.7
• https://github.com/sveltejs/svelte/security/advisories/GHSA-rcqx-6q8c-2c42
• https://access.redhat.com/security/cve/CVE-2026-42573
• https://bugzilla.redhat.com/show_bug.cgi?id=2487093
• https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-42573.json

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