{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "0"
              },
              {
                "last_affected": "2.1.0"
              }
            ],
            "source": [
              "AFFECTED_FIELD",
              "REFERENCES"
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "e5cab1e9a5dcea2bb3cbf888863fa7e65ab37edf"
            }
          ],
          "repo": "https://github.com/showdownjs/showdown",
          "type": "GIT"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "VulnCheck",
    "cwe_ids": [
      "CWE-79"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/59xxx/CVE-2026-59710.json"
  },
  "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.",
  "id": "CVE-2026-59710",
  "modified": "2026-08-07T11:31:06.980954071Z",
  "published": "2026-07-06T21:15:45.900Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/59xxx/CVE-2026-59710.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-59710"
    },
    {
      "type": "ADVISORY",
      "url": "https://www.vulncheck.com/advisories/showdown-stored-xss-via-unescaped-table-header-id-attribute-injection"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/showdownjs/showdown/issues/1046"
    },
    {
      "type": "FIX",
      "url": "https://github.com/showdownjs/showdown/commit/e5cab1e9a5dcea2bb3cbf888863fa7e65ab37edf"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/showdownjs/showdown"
    }
  ],
  "schema_version": "1.8.0",
  "severity": [
    {
      "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",
      "type": "CVSS_V4"
    }
  ],
  "summary": "showdown - Stored XSS via Unescaped Table Header ID Attribute Injection"
}