{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "0"
              },
              {
                "fixed": "1.13.0"
              }
            ],
            "source": [
              "AFFECTED_FIELD",
              "DESCRIPTION"
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "044fb58726f0b1d013276d41b3e54aa6dfd9ab4b"
            }
          ],
          "repo": "https://github.com/emilstenstrom/justhtml",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-5vp3-3cg6-2rq3"
  ],
  "database_specific": {
    "cna_assigner": "VulnCheck",
    "cwe_ids": [
      "CWE-80"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/5xxx/CVE-2026-5389.json"
  },
  "details": "justhtml versions before 1.13.0 contain a cross-site scripting vulnerability in the to_markdown() function when serializing attacker-controlled pre content. Attackers can place backticks inside sanitized pre elements to break out of fixed-length code fences, allowing raw HTML to execute when the generated Markdown is rendered by CommonMark or GFM-style renderers.",
  "id": "CVE-2026-5389",
  "modified": "2026-08-25T03:51:48.694323224Z",
  "published": "2026-08-23T13:34:09.865Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/5xxx/CVE-2026-5389.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/EmilStenstrom/justhtml/security/advisories/GHSA-5vp3-3cg6-2rq3"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-5389"
    },
    {
      "type": "ADVISORY",
      "url": "https://www.vulncheck.com/advisories/justhtml-before-xss-via-code-fence-breakout"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "justhtml before 1.13.0 XSS via code fence breakout"
}