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    CVE-2026-19931

    A flaw in libcurl makes it wrongly reuse an HTTP connection setup for a given hostname using Negotiate authentication, when the initial request is done using empty credentials. This can make user B's request get sent over user A's previously authenticated connection.

    Published:Sep 6, 2026
    Last Modified:Sep 15, 2026
    EPS:Sep 6, 2026
    EPSS Score:0.01162
    CVSS Score:9.8

    Affected Products

    Vendor
    Curl
    Product
    Curl
    Vendor
    Haxx
    Product
    Curl

    Exploits

    https://hackerone.com/reports/3923520https://hackerone.com/reports/3923520

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    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