{"id":"CVE-2026-86258","title":"nbviewer through 1.0.1 contains a path traversal vulnerability in LocalFileHandler.can_show() that uses string-prefix comparison instead of proper path validation","summary":"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 …","severity":"medium","cvss":5.9,"cvssVector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N","cwe":["CWE-22"],"vendor":"jupyter","product":"nbviewer","affected":["nbviewer <= 1.0.1"],"published":"2026-09-06","updated":"2026-09-10","sourceUpdated":"2026-09-10T16:18:02.407","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-86258","references":[{"url":"https://github.com/jupyter/nbviewer","label":"disclosure@vulncheck.com"},{"url":"https://github.com/jupyter/nbviewer/blob/1.0.1/nbviewer/providers/local/handlers.py#L92-L107","label":"disclosure@vulncheck.com"},{"url":"https://github.com/jupyter/nbviewer/commit/aad36106f72a1ca7721310c6fccc677ce4c744a5","label":"disclosure@vulncheck.com"},{"url":"https://github.com/jupyter/nbviewer/issues/1115","label":"disclosure@vulncheck.com"},{"url":"https://www.vulncheck.com/advisories/nbviewer-through-1.0.1-path-traversal-via-localfilehandler","label":"disclosure@vulncheck.com"}],"tags":["nvd","cve.org"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-09-10T14:19:03.319609Z"},"epss":0.00363,"epssPercentile":0.30134,"ingestedAt":"2026-09-07T05:05:30.497Z","slug":"CVE-2026-86258","body":"## Overview\n\nnbviewer 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":33,"depthScoreParts":{"impact":32.5,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}