CVE-2026-86258

nbviewer through 1.0.1 Path Traversal via LocalFileHandler

Published: Sep 6, 2026Updated: Sep 10, 2026 Sources: CVE List NVDCWE-22

5.9MEDIUM

Description

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.

No summary for this CVE yet.

CVSS Vector Breakdown

Exploitability

AV:NAttack Vector

Network

AC:HAttack Complexity

High

PR:NPrivileges Required

None

UI:NUser Interaction

None

Scope

S:UScope

Unchanged

Impact

C:HConfidentiality

High

I:NIntegrity

None

A:NAvailability

None

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Weaknesses

CWE-22

Affected Products

jupyter

oss-projectaka jupyter server, jupyterlab, notebook

nbviewerMixed

AI / ML / notebook-mlops

Exploitability

No known exploits, KEV entries, or remediation guidance available for this vulnerability yet.

Attack Graph

Products CVE Techniques Tactics

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MITRE ATT&CK

2 techniques

Collection

Discovery

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References

https://github.com/jupyter/nbviewer/issues/1115

github.com

https://github.com/jupyter/nbviewer/blob/1.0.1/nbviewer/providers/local/handlers.py#L92-L107

github.com

https://github.com/jupyter/nbviewer/commit/aad36106f72a1ca7721310c6fccc677ce4c744a5

github.com

and 2 more references View all →

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