CVE-2026-66339 | A flaw was found in libsoup. After a CONNECT tunnel is estab… | CVSS 6.5 MEDIUM

Description

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.

Metadata

CVE ID: CVE-2026-66339
State: PUBLISHED
Assigner: redhat
Reserved: 2026-07-24 22:32 UTC
Published: 2026-07-24 23:01 UTC
Last updated: 2026-07-24 23:01 UTC
Primary CWE: CWE-201
Insertion of Sensitive Information Into Sent Data
Vendor / Product: Red Hat / Red Hat Enterprise Linux 10
Sources: cve.org · NVD

Severity & Metrics

6.5 MEDIUM CVSS 3.1

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

Affected products (5)

Vendor	Product	Platform	Versions
Red Hat	Red Hat Enterprise Linux 10	—	—
Red Hat	Red Hat Enterprise Linux 6	—	—
Red Hat	Red Hat Enterprise Linux 7	—	—
Red Hat	Red Hat Enterprise Linux 8	—	—
Red Hat	Red Hat Enterprise Linux 9	—	—

Weakness (CWE)

CWE	Source	Description
CWE-201	cna	Insertion of Sensitive Information Into Sent Data

CVSS scores (1)

Score	Severity	Version	Source	Vector
6.5	MEDIUM	3.1	cna	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

References (2)