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OpenAdvisories
Medium · 5.4 CVE-2026-52816 EUVD-2026-39076GHSA-3w28-36p9-w929GO-2026-5103

Gogs: Unauthenticated Jupyter Notebook (ipynb) Sanitizer allows arbitrary data: URIs leading to XSS

Published Jun 24, 2026 · Updated Jun 25, 2026 · Assigned by GitHub_M

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.

Affected products

VendorProductAffectedFixed
gogs gogs < 0.14.3 —

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
openSUSE Leap 16.0 govulncheck-vulndb 0.0.20260723T184607-160000.1.1 openSUSE-SU-2026:21483-1

Affected packages

EcosystemPackageAffectedFixedRecord
Go gogs.io/gogs < 0.14.3 0.14.3 GHSA-3w28-36p9-w929
Go gogs.io/gogs all versions — GO-2026-5103

Advisories 2

References