CVE-2026-86258CWE-22

nbviewer through 1.0.1 Path Traversal via LocalFileHandler

Medium · published September 6, 2026

CVSS v3.1
5.9
EPSS
—
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
5.9 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
CVSS v4.0
8.2 · 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
EPSS
Not scored
Weakness
CWE-22 · Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Published
2026-09-06T12:37Z
Timeline
  • 06 SEP 12:37Z
    nbviewer through 1.0.1 Path Traversal via LocalFileHandler
    cvelistv5