What’s Vulnerable › Vulnerabilities

CVE-2026-52816: Gogs: Unauthenticated Jupyter Notebook (ipynb) Sanitizer allows arbitrary data: URIs leading to XSS

• Severity: medium (CVSS 5.4 v4.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.7% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-06-24 · updated 2026-06-25
• Weakness: CWE-80

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

• gogs: before 0.14.3

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

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