CVE-2026-42567

Summary

Svelte is a performance oriented web framework. From version 5.51.5 to before version 5.55.7, an internal regex in the Svelte runtime can take exponential time to test in <svelte:element this={tag}></svelte:element>. This issue has been patched in version 5.55.7.

Impact & exploitability

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products we track (1)

Recommendation

Apply the vendor fix promptly. Open any affected product above for its exact safe version.

Additional information

• NVD record
• https://github.com/sveltejs/svelte/security/advisories/GHSA-9rmh-mm8f-r9h6Advisory
• https://github.com/sveltejs/svelte/releases/tag/svelte%405.55.7