Curl 7.10.8 < 8.23.0 HTTP Proxy Credential Leak

high Nessus Plugin ID 371151

Synopsis

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

Description

The version of curl installed on the remote host is 7.10.8 prior to 8.23.0. It is, therefore, affected by an information disclosure vulnerability:

- An HTTP proxy can trick libcurl into sending the origin's credentials (Basic password, or a Negotiate/Kerberos ticket) to the proxy itself, by answering the CONNECT tunnel request with 401 WWW-Authenticate: instead of the expected 407 Proxy-Authenticate:. (CVE-2026-86414)

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

Solution

Upgrade Curl to version 8.23.0 or later.

See Also

https://curl.se/docs/CVE-2026-86414.html

Plugin Details

Severity: High

ID: 371151

File Name: curl_CVE-2026-86414.nasl

Version: 1.1

Type: Local

Agent: windows, macosx, unix

Family: Misc.

Published: 10/23/2026

Updated: 10/23/2026

Configuration: Enable thorough checks (optional)

Supported Sensors: Nessus Agent, Continuous Assessment, Tenable Cloud Security, Tenable Self-Hosted Container Security, Nessus

Risk Information

CVSS Score Rationale: Score from an analysis done by tenable

VPR

Risk Factor: Medium

Score: 4.9

Percentile: 58.42

CVSS v3

Risk Factor: High

Base Score: 7.5

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Vulnerability Information

CPE: cpe:/a:haxx:curl

Required KB Items: installed_sw/Curl

Patch Publication Date: 10/14/2026

Vulnerability Publication Date: 10/14/2026

Reference Information

CVE: CVE-2026-86414

IAVA: 2026-A-1143