CVE-2026-6658

{"id": "CVE-2026-6658", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-6658", "role": "CISA Coordinator", "options": [{"exploitation": "poc"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "version": "2.0.3", "timestamp": "2026-06-26T10:19:03.505659Z"}}], "cvssMetricV30": [{"type": "Secondary", "source": "security@huntr.dev", "cvssData": {"scope": "CHANGED", "version": "3.0", "baseScore": 5.4, "attackVector": "NETWORK", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.0/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N", "integrityImpact": "LOW", "userInteraction": "REQUIRED", "attackComplexity": "LOW", "availabilityImpact": "NONE", "privilegesRequired": "LOW", "confidentialityImpact": "LOW"}, "impactScore": 2.7, "exploitabilityScore": 2.3}]}, "affected": [{"source": "security@huntr.dev", "affectedData": [{"vendor": "jupyter", "product": "jupyter/jupyter", "versions": [{"status": "affected", "version": "unspecified", "versionType": "custom", "lessThanOrEqual": "latest"}]}]}], "published": "2026-06-26T10:16:22.810", "references": [{"url": "https://huntr.com/bounties/47570290-3b26-4477-8cfa-fdef7db5aefe", "source": "security@huntr.dev"}, {"url": "https://huntr.com/bounties/47570290-3b26-4477-8cfa-fdef7db5aefe", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"}], "vulnStatus": "Deferred", "weaknesses": [{"type": "Secondary", "source": "security@huntr.dev", "description": [{"lang": "en", "value": "CWE-79"}]}], "descriptions": [{"lang": "en", "value": "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. This vulnerability impacts any server using nbconvert to render notebooks as HTML, allowing attackers to execute arbitrary JavaScript in the context of users viewing the HTML export."}], "lastModified": "2026-06-26T20:08:23.053", "sourceIdentifier": "security@huntr.dev"}