CVE-2026-86258

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    CVE-2026-86258

    Published: 6 Sept 2026Last Modified: 25 Sept 2026

    Summary: nbviewer through 1.0.1 Path Traversal via LocalFileHandler

    Details: 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.

    References: https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/86xxx/CVE-2026-86258.json, https://nvd.nist.gov/vuln/detail/CVE-2026-86258, https://www.vulncheck.com/advisories/nbviewer-through-1.0.1-path-traversal-via-localfilehandler, https://github.com/jupyter/nbviewer/issues/1115, https://github.com/jupyter/nbviewer/commit/aad36106f72a1ca7721310c6fccc677ce4c744a5, https://github.com/jupyter/nbviewer, https://github.com/jupyter/nbviewer/blob/1.0.1/nbviewer/providers/local/handlers.py#L92-L107

    Affected packages

    Package

    Name:

    Purl:

    Affected ranges

    Type: GIT

    Events:

    Introduced- 0
    Fixed -1d2f3707404b880b5bbf2bb31914be19820c68ba

    Affected versions

    1.0.1
    1.0.0

    Common Vulnerability Scoring System

    Attack Vector
    Network
    Adjacent
    Local
    Physical
    Privileges Required
    None
    Low
    High
    User Interaction
    None
    Required
    Scope
    Unchanged
    Changed
    Confidentiality
    None
    Low
    High
    Integrity
    None
    Low
    High
    Availability
    None
    Low
    High
    CVE-2026-86258 | CVE-DB