Linux Distros Unpatched Vulnerability : CVE-2026-66339

high Nessus Plugin ID 329677

Synopsis

The Linux/Unix host has one or more packages installed with a vulnerability that the vendor indicates will not be patched.

Description

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

- A flaw was found in libsoup. After a CONNECT tunnel is established through an HTTP proxy, libsoup incorrectly attaches the Proxy-Authorization header to subsequent HTTPS requests sent through that tunnel to the destination server. This allows the destination server to capture proxy credentials, leading to information disclosure. (CVE-2026-66339)

Note that Nessus relies on the presence of the package as reported by the vendor.

Solution

There is no known solution at this time.

See Also

https://access.redhat.com/security/cve/cve-2026-66339

Plugin Details

Severity: High

ID: 329677

File Name: unpatched_CVE_2026_66339.nasl

Version: 1.1

Type: Local

Agent: unix

Family: Misc.

Published: 7/25/2026

Updated: 7/25/2026

Supported Sensors: Nessus Agent, Nessus

Risk Information

CVSS v2

Risk Factor: Medium

Base Score: 5

Temporal Score: 4.3

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

CVSS Score Source: CVE-2026-66339

CVSS v3

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.9

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

Temporal Vector: CVSS:3.0/E:U/RL:U/RC:C

Vulnerability Information

CPE: cpe:/o:centos:centos:7, cpe:/o:centos:centos:8, cpe:/o:redhat:enterprise_linux:10, cpe:/o:redhat:enterprise_linux:6, cpe:/o:redhat:enterprise_linux:7, cpe:/o:redhat:enterprise_linux:8, cpe:/o:redhat:enterprise_linux:9, p-cpe:/a:centos:centos:libsoup-devel, p-cpe:/a:centos:centos:libsoup3-devel, p-cpe:/a:centos:centos:libsoup3-doc, p-cpe:/a:centos:centos:libsoup3, p-cpe:/a:centos:centos:libsoup, p-cpe:/a:redhat:enterprise_linux:libsoup-devel, p-cpe:/a:redhat:enterprise_linux:libsoup3-devel, p-cpe:/a:redhat:enterprise_linux:libsoup3-doc, p-cpe:/a:redhat:enterprise_linux:libsoup3, p-cpe:/a:redhat:enterprise_linux:libsoup

Required KB Items: Host/cpu, Host/local_checks_enabled, global_settings/vendor_unpatched, Host/OS/identifier

Exploit Ease: No known exploits are available

Vulnerability Publication Date: 7/24/2026

Reference Information

CVE: CVE-2026-66339