PYSEC-2026-3731

    Dashboard / Vulnerabilities / PYSEC-2026-3731

    PYSEC-2026-3731

    Published: 22 Aug 2026Last Modified: 1 Sept 2026

    Summary:

    Details: NLTK versions before 3.10.0 contain a logic bug in FileSystemPathPointer.open() where the sandbox validation check compares a normalized path against itself, making the security check permanently inert. Attackers can pass file:// URLs to nltk.data.load() to read arbitrary files accessible to the process user, including credentials and configuration files.

    References: https://www.vulncheck.com/advisories/nltk-before-arbitrary-file-read-via-filesystempathpointer, https://github.com/nltk/nltk/security/advisories/GHSA-72r2-7mfr-5xr9

    Affected packages

    Package

    Name: nltk

    Purl: pkg:pypi/nltk

    Affected ranges

    Type: ECOSYSTEM

    Events:

    Introduced- 0
    Fixed -3.10.0

    Affected versions

    0.8

    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
    PYSEC-2026-3731 | CVE-DB