{"schemaVersion":3,"id":"CVE-2026-6658","aliases":["UBUNTU-CVE-2026-6658","DEBIAN-CVE-2026-6658","openSUSE-SU-2026:11725-1"],"status":"published","duplicateOf":null,"title":null,"description":"A vulnerability in jupyter/nbconvert versions <= 7.17.0 allows for Cross-site Scripting (XSS) via unsanitized `text/vnd.mermaid` output in HTML exports. The `data_mermaid` block in `share/templates/lab/base.html.j2` renders `text/vnd.mermaid` cell output directly into HTML without escaping, enabling attackers to inject arbitrary HTML/JavaScript by breaking out of the `<pre>` tag. 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