Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS) in gogs - CVE-2026-52816
Published: June 19, 2026
Vulnerability identifier: #VU134902
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2026-52816
CWE-ID: CWE-80
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: gogs.io
Affected software:
gogs
gogs
Detailed vulnerability description
The vulnerability allows a remote user to execute arbitrary JavaScript in the browser through cross-site scripting.
The vulnerability exists due to improper neutralization of script-related html tags in a web page in the POST /-/api/sanitize_ipynb endpoint when processing user-supplied ipynb content containing data: uris. A remote user can send crafted content to the sanitization endpoint to execute arbitrary JavaScript in the browser through cross-site scripting.
The issue stems from allowing unrestricted data: URIs, including data:text/html, in sanitized output.
How to mitigate CVE-2026-52816
Install security update from vendor's website.