THREATOPS
THREAT OPSThreat News › [NVD] CVE-2026-86258 (MEDIUM 5.9) — 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 roo

[NVD] CVE-2026-86258 (MEDIUM 5.9) — 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 roo

mednvdPublished 2026-09-06

CVE-2026-86258 CVSS: 5.9 MEDIUM Published: 2026-09-06T13:17:10.830

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 noteboo

MITRE ATT&CK techniques

Indicators of compromise

Original source: https://nvd.nist.gov/vuln/detail/CVE-2026-86258