{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-86258","assignerOrgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","state":"PUBLISHED","assignerShortName":"VulnCheck","dateReserved":"2026-09-06T11:35:19.317Z","datePublished":"2026-09-06T12:37:49.496Z","dateUpdated":"2026-09-24T14:21:19.100Z"},"containers":{"cna":{"providerMetadata":{"orgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","shortName":"VulnCheck","dateUpdated":"2026-09-24T14:21:19.100Z"},"datePublic":"2026-06-18T00:00:00.000Z","title":"nbviewer through 1.0.1 Path Traversal via LocalFileHandler","descriptions":[{"lang":"en","value":"nbviewer through 1.0.1 contains a path traversal vulnerability in LocalFileHandler.can_show() that uses string-prefix comparison instead of proper path validation. Attackers can read files from sibling directories outside the configured root by requesting paths that share the root as a textual prefix, disclosing unintended notebooks and credentials."}],"problemTypes":[{"descriptions":[{"lang":"en","description":"Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')","cweId":"CWE-22","type":"CWE"}]}],"affected":[{"vendor":"jupyter","product":"nbviewer","defaultStatus":"unaffected","packageURL":"pkg:pypi/nbviewer","versions":[{"version":"0","lessThanOrEqual":"1.0.1","status":"affected","versionType":"semver"}]}],"metrics":[{"format":"CVSS","cvssV4_0":{"version":"4.0","vectorString":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N","attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"PRESENT","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"HIGH","vulnIntegrityImpact":"NONE","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":8.2,"baseSeverity":"HIGH"}},{"format":"CVSS","cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N","attackVector":"NETWORK","attackComplexity":"HIGH","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"NONE","availabilityImpact":"NONE","baseScore":5.9,"baseSeverity":"MEDIUM"}}],"references":[{"url":"https://github.com/jupyter/nbviewer/issues/1115","tags":["issue-tracking"],"name":"GitHub Issue #1115"},{"url":"https://github.com/jupyter/nbviewer/blob/1.0.1/nbviewer/providers/local/handlers.py#L92-L107","tags":["technical-description"],"name":"LocalFileHandler.can_show() at 1.0.1"},{"url":"https://github.com/jupyter/nbviewer/commit/aad36106f72a1ca7721310c6fccc677ce4c744a5","tags":["patch"],"name":"Fix path-containment bypass in LocalFileHandler.can_show (PR #1116)"},{"url":"https://github.com/jupyter/nbviewer","tags":["product"]},{"name":"VulnCheck Advisory: nbviewer through 1.0.1 Path Traversal via LocalFileHandler","tags":["third-party-advisory"],"url":"https://www.vulncheck.com/advisories/nbviewer-through-1.0.1-path-traversal-via-localfilehandler"}],"credits":[{"lang":"en","value":"Yu Sun","type":"finder"}],"x_generator":{"engine":"vulncheck-endgame"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-09-10T14:19:03.319609Z","id":"CVE-2026-86258","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-09-10T15:04:32.871Z"}}]}}