CVE-2026-66339
MEDIUMLibsoup: libsoup: proxy credentials leak to destination server via proxy-authorization header in connect tunnels
Title source: cnaDescription
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.
References (2)
Core 2
Core References
Vdb Entry, X_Refsource_Redhat vdb-entry
x_refsource_redhat
https://access.redhat.com/security/cve/CVE-2026-66339
Issue Tracking, X_Refsource_Redhat issue-tracking
x_refsource_redhat
RHBZ#2506951
https://bugzilla.redhat.com/show_bug.cgi?id=2506951
Scores
CVSS v3
6.5
EPSS
0.0023
EPSS Percentile
13.9%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
no
Technical Impact
partial
Details
CWE
CWE-201
Status
published
Products (5)
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
Published
Jul 24, 2026
Tracked Since
Jul 25, 2026