{"cve":"CVE-2026-52816","nvd":{"published":"2026-06-24T21:16:57.753","modified":"2026-06-25T21:16:27.447","status":"Deferred","description":"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.","cvss_v4":{"vector":"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","score":5.4},"cvss_v3":null,"cwes":["CWE-80"],"references":["https://github.com/gogs/gogs/commit/dd1bd9837aa196b3ed3a8ee21e5727b5d7a986a3","https://github.com/gogs/gogs/pull/8326","https://github.com/gogs/gogs/releases/tag/v0.14.3","https://github.com/gogs/gogs/security/advisories/GHSA-3w28-36p9-w929","https://github.com/gogs/gogs/security/advisories/GHSA-3w28-36p9-w929"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:41:17.107060303+00:00"},"epss":{"cve":"CVE-2026-52816","score":0.00677,"percentile":0.52276,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-3w28-36p9-w929","url":"https://osv.dev/vulnerability/GHSA-3w28-36p9-w929","summary":"Gogs's Unauthenticated Jupyter Notebook (ipynb) Sanitizer allows arbitrary data: URIs leading to XSS","modified":"2026-07-21T13:30:31.797159202Z","packages":[{"ecosystem":"Go","name":"gogs.io/gogs","purl":"pkg:golang/gogs.io/gogs","ranges":["<0.14.3"],"fixed":["0.14.3"]}]},{"id":"GO-2026-5103","url":"https://osv.dev/vulnerability/GO-2026-5103","summary":"Gogs's Unauthenticated Jupyter Notebook (ipynb) Sanitizer allows arbitrary data: URIs leading to XSS in gogs.io/gogs","modified":"2026-06-25T18:45:20.971723002Z","packages":[{"ecosystem":"Go","name":"gogs.io/gogs","purl":"pkg:golang/gogs.io/gogs","ranges":["all versions"],"fixed":[]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}