XSS in Gogs

CVE-2026-52798

Gogs is an open source self-hosted Git service. Prior to 0.14.3, although .ipynb previews are sanitized on the server side via /-/api/sanitize_ipynb, the inserted content is re-rendered on the client side without sanitization using marked() on elements with the .nb-markdown-cell class. During this process, links containing schemes such as javascript: can be regenerated. As a result, when a victim views an attacker-crafted .ipynb file and clicks the link, arbitrary JavaScript is executed in the Gogs origin, leading to a click-based Stored XSS. This vulnerability is fixed in 0.14.3.

Vulnerability class: XSS (Cross-Site Scripting)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 8.9 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:L.

EPSS exploit prediction

EPSS: 0.004 (34.7th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 35th percentile — 34.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-52798: held from 0.004 to 0.004.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000

Affected products

  • Gogs — versions < 0.14.3

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-52798?
CVE-2026-52798 is a high-severity vulnerability in Gogs, classified under Cross-site Scripting. CVSS score: 8.9/10. Published 2026-06-24.
How severe is CVE-2026-52798?
High severity. CVSS v3 base score is 8.9 out of 10.