{"id":"CVE-2026-52816","summary":"Gogs: Unauthenticated Jupyter Notebook (ipynb) Sanitizer allows arbitrary data: URIs leading to XSS","details":"Gogs is an open source self-hosted Git service. Prior to 0.14.3, the Jupyter Notebook (ipynb) sanitizer endpoint at POST /-/api/sanitize_ipynb allows arbitrary data: URIs without proper restrictions, potentially leading to Cross-Site Scripting (XSS). The endpoint uses bluemonday.UGCPolicy() with p.AllowURLSchemes(\"data\") which permits all data URI schemes including data:text/html, enabling attackers to inject malicious HTML/JavaScript. Additionally, the endpoint has no authentication middleware, allowing any registered user to exploit this vulnerability. This vulnerability is fixed in 0.14.3.","aliases":["GHSA-3w28-36p9-w929","GO-2026-5103"],"modified":"2026-08-04T11:50:33.676494235Z","published":"2026-06-24T20:26:34.151Z","related":["openSUSE-SU-2026:21483-1"],"database_specific":{"cna_assigner":"GitHub_M","cwe_ids":["CWE-80"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/52xxx/CVE-2026-52816.json"},"references":[{"type":"WEB","url":"https://github.com/gogs/gogs/releases/tag/v0.14.3"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/52xxx/CVE-2026-52816.json"},{"type":"ADVISORY","url":"https://github.com/gogs/gogs/security/advisories/GHSA-3w28-36p9-w929"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-52816"},{"type":"FIX","url":"https://github.com/gogs/gogs/commit/dd1bd9837aa196b3ed3a8ee21e5727b5d7a986a3"},{"type":"FIX","url":"https://github.com/gogs/gogs/pull/8326"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/gogs/gogs","events":[{"introduced":"0"},{"fixed":"3ba8aca90e17e5410b7e8b227c9f29256ac3e875"}],"database_specific":{"extracted_events":[{"introduced":"0"},{"fixed":"0.14.3"}],"source":"AFFECTED_FIELD"}}],"versions":["v0.14.2-rc.1","v0.14.2","v0.14.1-rc.1","v0.14.1","v0.14.0-rc.1","v0.14.0","v0.11.91","v0.11.86","v0.11.79","v0.11.66","v0.11.53","v0.11.43","v0.11.34","v0.11.33","v0.11.29","v0.11.19","v0.11.4","v0.11","v0.11rc","v0.10.18","v0.10.8","v0.10","v0.10rc","v0.9.141","v0.9.128","v0.9.113","v0.9.97","v0.9.71","v0.9.60","v0.9.48","v0.9.46","v0.9.13","v0.9.0","v0.8.43","v0.8.25","v0.8.10","v0.8.0","v0.7.33","v0.7.22","v0.7.19","v0.7.6","v0.7.0","v0.6.15","v0.6.9","v0.6.3","v0.6.1","v0.5.13","v0.5.11","v0.5.9","v0.5.8","v0.5.5","v0.5.2","v0.5.0","v0.4.2","v0.4.1","v0.4.0","v0.3.1","v0.3.0","v0.2.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-52816.json"}}],"schema_version":"1.8.0","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N/E:P"}]}