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.

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Advisories
Source ID Title
Ubuntu USN Ubuntu USN USN-8890-1 libsoup vulnerabilities
Ubuntu USN Ubuntu USN USN-8890-2 libsoup vulnerabilities
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Fri, 06 Nov 2026 19:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Thu, 05 Nov 2026 22:30:00 +0000

Type Values Removed Values Added
First Time appeared Redhat rhel Els
CPEs 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
cpe:/a:redhat:enterprise_linux:10
cpe:/a:redhat:enterprise_linux:8
cpe:/a:redhat:enterprise_linux:9
cpe:/o:redhat:rhel_els:6
cpe:/o:redhat:rhel_els:7
Vendors & Products Redhat rhel Els

Mon, 24 Aug 2026 17:00:00 +0000

Type Values Removed Values Added
First Time appeared Gnome
Gnome libsoup
CPEs cpe:2.3:a:gnome:libsoup:-:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux:10.0:*:*:*:*:*:*:*
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:*:*:*:*:*:*:*
Vendors & Products Gnome
Gnome libsoup

Mon, 27 Jul 2026 15:45:00 +0000

Type Values Removed Values Added
First Time appeared Libsoup
Libsoup libsoup
Vendors & Products Libsoup
Libsoup libsoup

Fri, 24 Jul 2026 23:15:00 +0000

Type Values Removed Values Added
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.
Title Libsoup: libsoup: proxy credentials leak to destination server via proxy-authorization header in connect tunnels
First Time appeared Redhat
Redhat enterprise Linux
Weaknesses CWE-201
CPEs 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
Vendors & Products Redhat
Redhat enterprise Linux
References
Metrics cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: redhat

Published:

Updated: 2026-11-05T22:13:11.800Z

Reserved: 2026-07-24T22:32:18.748Z

Link: CVE-2026-66339

cve-icon Vulnrichment

Updated: 2026-07-28T14:25:50.675Z

cve-icon NVD

Status : Analyzed

Published: 2026-07-24T23:16:52.187

Modified: 2026-11-05T23:16:56.133

Link: CVE-2026-66339

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-08-03T19:45:07Z

Weaknesses