CVE-2025-62780: Changedetection.io Cross-Site Scripting Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-4c3j-3h7v-22q9",
  "modified" : "2026-06-05T14:17:15Z",
  "published" : "2025-11-12T21:24:57Z",
  "aliases" : [ "CVE-2025-62780" ],
  "summary" : "changedetection.io: Stored XSS in Watch update via API",
  "details" : "### Summary\n\nA Stored Cross Site Scripting is present in the changedetection.io Watch update API due to unsufficient security checks.\n\n### Details\n\nTested on changedetection.io version *v0.50.24*\n\n```console\nREPOSITORY                            TAG       IMAGE ID       CREATED        SIZE\nghcr.io/dgtlmoon/changedetection.io   latest    0367276509a0   23 hours ago   599MB\n```\n\nWhen a user tries to add an unsafe URL as a Watch in the changedetection.io UI, the action is blocked with the error message \"Watch protocol is not permitted by SAFE_PROTOCOL_REGEX or incorrect URL format\".\nThis is catched by the function `validate_url(test_url)`.\n\n```python\ndef validate_url(test_url):\n    # ...\n    from .model.Watch import is_safe_url\n    if not is_safe_url(test_url):\n        # This should be wtforms.validators.\n        raise ValidationError('Watch protocol is not permitted by SAFE_PROTOCOL_REGEX or incorrect URL format')\n```\n\nWhen instead the Watch API is used, this check is not performed resulting in unsafe URLs added as Watch.\n\n### PoC\n\nUpdate an existing watch with an unsafe URL\n```console\ncurl -X PUT \"http://example.site/api/v1/watch/1242e1c5-d59e-4352-0078-203a55b21282\" \\\n  -H \"x-api-key: XXX\" \\\n  -H \"Content-Type: application/json\" \\\n  -d '{\n    \"url\": \"javascript:alert(document.domain)\",\n    \"title\": \"XSS PoC\",\n    \"paused\": false\n  }'\n```\n\n### Impact\n\nTwo scenarios are possibile:\n\n1. An attacker can insert a new watch with an arbitrary URL which really points to a web page. Once the HTML content is retrieved, the attacker updates the URL with a JavaScript payload.\n2. An attacker substitutes the URL in an existing watch with a new URL that is in reality a JavaScript payload.\n\nWhen the user clicks on *Preview* and then on the malicious link, the JavaScript malicious code is executed.\n\n<img width=\"1200\" height=\"643\" alt=\"poc1\" src=\"https://github.com/user-attachments/assets/db81e0c7-b6d3-4332-b15d-a688a48c3227\" />\n<br>\n<img width=\"1200\" height=\"643\" alt=\"poc2\" src=\"https://github.com/user-attachments/assets/e704b37c-d339-4322-9fc0-ad50dd86b31d\" />\n\n\n\n### Credits\n\nEdoardo Ottavianelli @edoardottt",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:L/I:L/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "changedetection.io"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.50.34"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/dgtlmoon/changedetection.io/security/advisories/GHSA-4c3j-3h7v-22q9"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2025-62780"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/dgtlmoon/changedetection.io/issues/3562"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/dgtlmoon/changedetection.io/pull/3564"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/dgtlmoon/changedetection.io"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/dgtlmoon/changedetection.io/releases/tag/0.50.34"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/pypa/advisory-database/tree/main/vulns/changedetection-io/PYSEC-2025-91.yaml"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-79" ],
    "severity" : "LOW",
    "github_reviewed" : true,
    "github_reviewed_at" : "2025-11-12T21:24:57Z",
    "nvd_published_at" : "2025-11-10T22:15:36Z"
  }
}