{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "0"
              },
              {
                "last_affected": "2.4.0"
              }
            ],
            "source": "AFFECTED_FIELD"
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "last_affected": "9f3b837c8c7f359ec1acee80b3c0430451986a03"
            }
          ],
          "repo": "https://github.com/louislam/uptime-kuma",
          "type": "GIT"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "TuranSec",
    "cwe_ids": [
      "CWE-79"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/71xxx/CVE-2026-71285.json"
  },
  "details": "Uptime Kuma's Matomo analytics integration (server/analytics/matomo-analytics.js) injects the admin-configurable Matomo `siteId` value as a bare, unquoted JavaScript expression inside a \u003cscript\u003e block rendered on every public status page: `_paq.push(['setSiteId', ${escapedSiteIdHTMLAttribute}]);`. The escaping pipeline used (jsesc with isScriptContext:true, then html-escaper.escape()) does not escape the characters `]`, `)`, `;`, `(`, which are sufficient to break out of the array/push expression context. A siteId value such as `1]);alert(document.cookie)//`, once saved by an editor/admin, executes arbitrary JavaScript for every unauthenticated visitor of the public /status/\u003cslug\u003e page, enabling session-cookie theft and full page takeover.",
  "id": "CVE-2026-71285",
  "modified": "2026-08-07T03:30:27.792443248Z",
  "published": "2026-08-05T12:26:30.908Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/louislam/uptime-kuma/blob/master/server/analytics/matomo-analytics.js"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/71xxx/CVE-2026-71285.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-71285"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/louislam/uptime-kuma"
    }
  ],
  "schema_version": "1.8.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:H/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Uptime Kuma Stored XSS via Matomo Analytics Site ID on Public Status Pages"
}