CVE-2026-66339

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.

CVSS v3 6.5 MEDIUM

6.5^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.8 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction REQUIRED

Confidentiality Impact HIGH

Integrity Impact NONE

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://access.redhat.com/security/cve/CVE-2026-66339	Vendor Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2506951	Issue Tracking Vendor Advisory Exploit Mitigation

Configurations

Configuration 1 (hide)

OR	cpe:2.3:a:gnome:libsoup:-:::::::*
	cpe:2.3:o:redhat:enterprise_linux:6.0:::::::*
	cpe:2.3:o:redhat:enterprise_linux:7.0:::::::*
	cpe:2.3:o:redhat:enterprise_linux:8.0:::::::*
	cpe:2.3:o:redhat:enterprise_linux:9.0:::::::*
	cpe:2.3:o:redhat:enterprise_linux:10.0:::::::*

History

No history.

Information

Published : 2026-07-24 23:16

Updated : 2026-08-24 16:44

NVD link : CVE-2026-66339

Mitre link : CVE-2026-66339

CVE.ORG link : CVE-2026-66339

JSON object : View

Products Affected

redhat

enterprise_linux

gnome

libsoup

CWE

CWE-201

Insertion of Sensitive Information Into Sent Data

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