Svelte: ReDoS in `` Tag Validation_CVE-2026-42567

5.9 / 10

MEDIUM

CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Description

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.

Basic Information

ID CVE-2026-42567

Source GitHub_M

Published Jun 9, 2026 at 16:22

Affected Product

Vendor sveltejs

Product svelte

Version >= 5.51.5, < 5.55.7

Affected Versions sveltejs svelte >= 5.51.5, < 5.55.7

CWE Classification

CWE-1333

References

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    "published": "2026-06-09T16:22:22.703Z",
    "modified": "2026-06-09T16:22:22.703Z",
    "type": "cve",
    "title": "Svelte: ReDoS in `<svelte:element>` Tag Validation",
    "source": "GitHub_M",
    "references": "https://github.com/sveltejs/svelte/security/advisories/GHSA-9rmh-mm8f-r9h6\nhttps://github.com/sveltejs/svelte/releases/tag/svelte%405.55.7",
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