{
"id": "GHSA-22g5-r2x5-97cx",
"aliases": [
"CVE-2026-59710"
],
"details": "showdown contains a stored cross-site scripting vulnerability in the parseHeaders function of src/subParsers/makehtml/tables.js that fails to properly escape table header ID attributes. Attackers can inject arbitrary HTML and script-executing SVG elements through double-quote characters in markdown table headers, achieving stored XSS when untrusted markdown is rendered with the default github flavor configuration.",
"summary": "showdown allows stored cross-site scripting through table header ID injection",
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"last_affected": "2.1.0"
}
]
}
],
"package": {
"name": "showdown",
"ecosystem": "npm"
}
}
],
"modified": "2026-08-07T21:03:43Z",
"severity": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N"
},
{
"type": "CVSS_V4",
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N"
}
],
"published": "2026-07-07T00:30:59Z",
"references": [
{
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-59710",
"type": "ADVISORY"
},
{
"url": "https://github.com/showdownjs/showdown/issues/1046",
"type": "WEB"
},
{
"url": "https://github.com/showdownjs/showdown/commit/e5cab1e9a5dcea2bb3cbf888863fa7e65ab37edf",
"type": "WEB"
},
{
"url": "https://github.com/showdownjs/showdown",
"type": "PACKAGE"
},
{
"url": "https://www.vulncheck.com/advisories/showdown-stored-xss-via-unescaped-table-header-id-attribute-injection",
"type": "WEB"
}
],
"schema_version": "1.4.0",
"database_specific": {
"cwe_ids": [
"CWE-79"
],
"severity": "MODERATE",
"github_reviewed": true,
"nvd_published_at": "2026-07-06T22:16:50Z",
"github_reviewed_at": "2026-08-07T21:03:43Z"
}
}