{"id":"CVE-2025-62780","aliases":["GHSA-4c3j-3h7v-22q9","PYSEC-2025-91"],"url":"https://o3.security/vulnerability/CVE-2025-62780","summary":"changedetection.io vulnerable to 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","published":"2025-11-10T21:18:52.945Z","modified":"2026-08-12T03:51:22.439159208Z","cvss":{"score":3.5,"severity":"LOW","vector":"CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:L/I:L/A:N"},"epss":{"score":0.00431,"percentile":0.35858,"asOf":"2026-08-27"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"PyPI","name":"changedetection-io","fixedVersion":"0.50.34"}],"fix":{"url":"https://github.com/dgtlmoon/changedetection.io/pull/3564","label":"dgtlmoon/changedetection.io#3564"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/62xxx/CVE-2025-62780.json"},{"type":"ADVISORY","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"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:22.439159208Z"}}