{"id":"CVE-2026-52816","aliases":["GHSA-3w28-36p9-w929","GO-2026-5103"],"url":"https://o3.security/vulnerability/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.","published":"2026-06-24T20:26:34.151Z","modified":"2026-08-12T03:51:22.213937684Z","cvss":null,"epss":{"score":0.00677,"percentile":0.49993,"asOf":"2026-09-08"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Go","name":"gogs.io/gogs","fixedVersion":"0.14.3"}],"fix":{"url":"https://github.com/gogs/gogs/commit/dd1bd9837aa196b3ed3a8ee21e5727b5d7a986a3","label":"gogs/gogs@dd1bd98"},"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"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:22.213937684Z"}}