libcurl 7.64.1 < 8.22.0 Negotiate Ambient User Connection Reuse

medium Nessus Plugin ID 342615

Synopsis

The remote host has a program that is affected by an information disclosure vulnerability.

Description

The version of libcurl installed on the remote host is 7.64.1 prior to 8.22.0. It is, therefore, affected by an information disclosure vulnerability:

- 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. (CVE-2026-19931)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

Solution

Upgrade libcurl to version 8.22.0 or later.

Plugin Details

Severity: Medium

ID: 342615

File Name: libcurl_CVE-2026-19931.nasl

Version: 1.1

Type: Local

Agent: windows, macosx, unix

Family: Misc.

Published: 9/3/2026

Updated: 9/3/2026

Configuration: Enable thorough checks (optional)

Supported Sensors: Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 4.9

Percentile: 58.17

CVSS v4

Risk Factor: Medium

Base Score: 5.3

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N

Vulnerability Information

CPE: cpe:/a:haxx:libcurl

Required KB Items: installed_sw/libcurl

Patch Publication Date: 9/2/2026

Vulnerability Publication Date: 9/2/2026

Reference Information

CVE: CVE-2026-19931

Detections

Analytics