{
"id": "GHSA-9rmh-mm8f-r9h6",
"aliases": [
"CVE-2026-42567"
],
"details": "An internal regex in the Svelte runtime can take exponential time to test in `<svelte:element this={tag}></svelte:element>`. You are only vulnerable to this if you allow tags of unconstrained length. If your application only allows a predetermined list of tags or trims their length before passing them to `svelte:element`, you are safe.",
"summary": "Svelte: ReDoS in `<svelte:element>` Tag Validation",
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "5.51.5"
},
{
"fixed": "5.55.7"
}
]
}
],
"package": {
"name": "svelte",
"ecosystem": "npm"
},
"database_specific": {
"last_known_affected_version_range": "<= 5.55.6"
}
}
],
"modified": "2026-06-09T18:41:19Z",
"severity": [
{
"type": "CVSS_V4",
"score": "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"
}
],
"published": "2026-05-14T20:29:05Z",
"references": [
{
"url": "https://github.com/sveltejs/svelte/security/advisories/GHSA-9rmh-mm8f-r9h6",
"type": "WEB"
},
{
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-42567",
"type": "ADVISORY"
},
{
"url": "https://github.com/sveltejs/svelte",
"type": "PACKAGE"
},
{
"url": "https://github.com/sveltejs/svelte/releases/tag/svelte%405.55.7",
"type": "WEB"
}
],
"schema_version": "1.4.0",
"database_specific": {
"cwe_ids": [
"CWE-1333"
],
"severity": "MODERATE",
"github_reviewed": true,
"nvd_published_at": "2026-06-09T17:17:07Z",
"github_reviewed_at": "2026-05-14T20:29:05Z"
}
}