Detections
Analytics

Curl 7.30.0 < 8.21.0 Wrong STARTTLS Connection Reuse

high Nessus Plugin ID 323003

Synopsis

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

Description

The version of curl installed on the remote host is 7.30.0 prior to 8.21.0. It is, therefore, affected by an improper certificate validation vulnerability:

 - A vulnerability exists where a new transfer that uses STARTTLS to upgrade the connection might reuse an existing live connection even though the TLS configuration mismatches so it should not.
 (CVE-2026-8286)

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 8.21.0 or later.

See Also

https://curl.se/docs/CVE-2026-8286.html

Plugin Details

Severity: High

ID: 323003

File Name: curl_CVE-2026-8286.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: Continuous Assessment, Nessus Agent, tenable_cloud_security, tenable_self_hosted_container_security, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 5.0

CVSS v2

Risk Factor: Medium

Base Score: 6.4

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

CVSS Score Source: CVE-2026-8286

CVSS v3

Risk Factor: High

Base Score: 7.5

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

Vulnerability Information

CPE: cpe:/a:haxx:curl

Required KB Items: installed_sw/Curl

Patch Publication Date: 6/24/2026

Vulnerability Publication Date: 6/24/2026

Reference Information

CVE: CVE-2026-8286

IAVA: 2026-A-0627