{"id":"GHSA-4c3j-3h7v-22q9","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\u003cimg width=\"1200\" height=\"643\" alt=\"poc1\" src=\"https://github.com/user-attachments/assets/db81e0c7-b6d3-4332-b15d-a688a48c3227\" /\u003e\n\u003cbr\u003e\n\u003cimg width=\"1200\" height=\"643\" alt=\"poc2\" src=\"https://github.com/user-attachments/assets/e704b37c-d339-4322-9fc0-ad50dd86b31d\" /\u003e\n\n\n\n### Credits\n\nEdoardo Ottavianelli @edoardottt","aliases":["CVE-2025-62780","PYSEC-2025-91"],"modified":"2026-06-05T14:30:14.151541624Z","published":"2025-11-12T21:24:57Z","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"},"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"}],"affected":[{"package":{"name":"changedetection-io","ecosystem":"PyPI","purl":"pkg:pypi/changedetection-io"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.50.34"}]}],"versions":["0.38.2","0.39","0.39.1","0.39.10","0.39.10.post1","0.39.10.post2","0.39.11","0.39.12","0.39.13","0.39.13.1","0.39.14","0.39.14.1","0.39.15","0.39.16","0.39.17","0.39.17.1","0.39.17.2","0.39.18","0.39.19","0.39.19.1","0.39.2","0.39.20","0.39.20.1","0.39.20.2","0.39.20.3","0.39.20.4","0.39.21","0.39.21.1","0.39.22","0.39.22.1","0.39.3","0.39.4","0.39.5","0.39.6","0.39.7","0.39.8","0.39.9","0.40.0","0.40.0.1","0.40.0.2","0.40.0.3","0.40.0.4","0.40.1.0","0.40.1.1","0.40.2","0.40.3","0.41","0.41.1","0.42","0.42.1","0.42.2","0.42.3","0.43.1","0.43.2","0.44","0.44.1","0.45","0.45.1","0.45.11","0.45.12","0.45.13","0.45.14","0.45.15","0.45.16","0.45.17","0.45.18","0.45.19","0.45.2","0.45.20","0.45.21","0.45.22","0.45.23","0.45.24","0.45.25","0.45.26","0.45.3","0.45.4","0.45.5","0.45.6","0.45.7","0.45.7.1","0.45.7.2","0.45.7.3","0.45.8","0.45.8.1","0.45.9","0.46.0","0.46.1","0.46.2","0.46.3","0.46.4","0.47.0","0.47.1","0.47.2","0.47.3","0.47.4","0.47.5","0.47.6","0.48.0","0.48.1","0.48.2","0.48.3","0.48.4","0.48.5","0.48.6","0.49.0","0.49.1","0.49.10","0.49.12","0.49.13","0.49.14","0.49.15","0.49.16","0.49.17","0.49.18","0.49.2","0.49.3","0.49.4","0.49.5","0.49.6","0.49.7","0.49.8","0.49.9","0.50.1","0.50.10","0.50.11","0.50.12","0.50.13","0.50.14","0.50.15","0.50.16","0.50.17","0.50.18","0.50.19","0.50.2","0.50.20","0.50.21","0.50.22","0.50.23","0.50.24","0.50.25","0.50.26","0.50.27","0.50.28","0.50.29","0.50.3","0.50.30","0.50.31","0.50.32","0.50.33","0.50.4","0.50.5","0.50.6","0.50.7","0.50.8","0.50.9"],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2025/11/GHSA-4c3j-3h7v-22q9/GHSA-4c3j-3h7v-22q9.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:L/I:L/A:N"}]}