Detections
Analytics

libcurl 7.69.0 < 8.21.0 SSH Improper Host Validation

critical Nessus Plugin ID 323010

Synopsis

The remote host has a program that is affected by an improper host validation vulnerability.

Description

The version of libcurl installed on the remote host is 7.69.0 prior to 8.21.0. It is, therefore, affected by an improper host validation vulnerability:

 - When a libcurl-based application performs transfers via SCP or SFTP and utilizes the CURLOPT_SSH_KEYFUNCTION callback, it may silently accept an untrusted server. (CVE-2026-9547)

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 8.21.0 or later.

See Also

https://curl.se/docs/CVE-2026-9547.html

Plugin Details

Severity: Critical

ID: 323010

File Name: libcurl_CVE-2026-9547.nasl

Version: 1.1

Type: Local

Agent: windows, macosx, unix

Family: Misc.

Published: 6/26/2026

Updated: 6/26/2026

Configuration: Enable thorough checks (optional)

Supported Sensors: Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: High

Score: 7.4

CVSS v2

Risk Factor: High

Base Score: 7.5

Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P

CVSS Score Source: CVE-2026-9547

CVSS v3

Risk Factor: Critical

Base Score: 9.8

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

Vulnerability Information

CPE: cpe:/a:haxx:libcurl

Required KB Items: installed_sw/libcurl

Patch Publication Date: 6/24/2026

Vulnerability Publication Date: 6/24/2026

Reference Information

CVE: CVE-2026-9547

IAVA: 2026-A-0627