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OpenAdvisories
Medium · 6.5 CVE-2026-66339 EUVD-2026-48751GHSA-vh9q-f797-xwg7

Libsoup: libsoup: proxy credentials leak to destination server via proxy-authorization header in connect tunnels

Published Jul 24, 2026 · Updated Nov 5, 2026 · Assigned by redhat

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.

Affected products

VendorProductAffectedFixed
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 — —

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
Debian 13 libsoup3 +1 No fix yet —
Debian 12 libsoup3 +1 No fix yet —
ReleasePackageFixed inAdvisory
Ubuntu 26.10 libsoup2.4 No fix yet —
Ubuntu 26.10 libsoup3 3.6.6-1ubuntu3 USN-8890-2
Ubuntu 26.04 LTS libsoup3 3.6.6-1ubuntu0.1 USN-8890-1
Ubuntu 24.04 LTS libsoup2.4 2.74.3-6ubuntu1.9 USN-8890-1
Ubuntu 24.04 LTS libsoup3 3.4.4-5ubuntu0.9 USN-8890-1
Ubuntu 22.04 LTS libsoup2.4 2.74.2-3ubuntu0.9 USN-8890-1
Show 5 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
Ubuntu Pro 26.04 LTS libsoup2.4 2.74.3-10.1ubuntu5+esm3 USN-8890-1
Ubuntu Pro 22.04 LTS libsoup3 3.0.7-0ubuntu1+esm9 USN-8890-1
Ubuntu Pro 20.04 LTS libsoup2.4 2.70.0-1ubuntu0.5+esm4 USN-8890-1
Ubuntu Pro 18.04 LTS libsoup2.4 2.62.1-1ubuntu0.4+esm9 USN-8890-1
Ubuntu Pro 16.04 LTS libsoup2.4 2.52.2-1ubuntu0.3+esm8 USN-8890-1
ReleasePackageFixed inAdvisory
SLES 15 SP7 libsoup 3.4.4-150600.3.56.1 SUSE-SU-2026:4558-1
SLES 15 SP7 libsoup2 2.74.3-150600.4.42.1 SUSE-SU-2026:4703-1
SLES 15 SP6 libsoup 3.4.4-150600.3.56.1 SUSE-SU-2026:4558-1
SLES 15 SP6 libsoup2 2.74.3-150600.4.42.1 SUSE-SU-2026:4703-1
SLES 15 SP5 libsoup 3.0.4-150400.3.52.1 SUSE-SU-2026:4557-1
SLES 15 SP5 libsoup2 2.74.3-150400.3.43.1 SUSE-SU-2026:4739-1
SLES 15 SP4 libsoup 3.0.4-150400.3.52.1 SUSE-SU-2026:4557-1
SLES 15 SP4 libsoup2 2.74.3-150400.3.43.1 SUSE-SU-2026:4739-1
SLES 12 SP5 libsoup 2.62.2-5.49.1 SUSE-SU-2026:4690-1
Show 11 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
SLES for SAP 16.0 libsoup 3.6.6-160000.5.1 SUSE-SU-2026:24470-1
SLES for SAP 15 SP6 libsoup 3.4.4-150600.3.56.1 SUSE-SU-2026:4558-1
SLES for SAP 15 SP6 libsoup2 2.74.3-150600.4.42.1 SUSE-SU-2026:4703-1
SLES for SAP 15 SP5 libsoup 3.0.4-150400.3.52.1 SUSE-SU-2026:4557-1
SLES for SAP 15 SP5 libsoup2 2.74.3-150400.3.43.1 SUSE-SU-2026:4739-1
SLES for SAP 15 SP4 libsoup 3.0.4-150400.3.52.1 SUSE-SU-2026:4557-1
SLES for SAP 15 SP4 libsoup2 2.74.3-150400.3.43.1 SUSE-SU-2026:4739-1
SLES 16.0 libsoup 3.6.6-160000.5.1 SUSE-SU-2026:24470-1
SLE Micro 6.0 libsoup 3.4.2-159998.1.1 SUSE-SU-2026:24368-1
SLE Micro 5.5 libsoup2 2.74.3-150400.3.43.1 SUSE-SU-2026:4739-1
SLE Micro 5.4 libsoup2 2.74.3-150400.3.43.1 SUSE-SU-2026:4739-1
SLE Micro 5.3 libsoup2 2.74.3-150400.3.43.1 SUSE-SU-2026:4739-1
SLE HPC 15 SP5 libsoup 3.0.4-150400.3.52.1 SUSE-SU-2026:4557-1
SLE HPC 15 SP5 libsoup2 2.74.3-150400.3.43.1 SUSE-SU-2026:4739-1
SLE HPC 15 SP4 libsoup 3.0.4-150400.3.52.1 SUSE-SU-2026:4557-1
SLE HPC 15 SP4 libsoup2 2.74.3-150400.3.43.1 SUSE-SU-2026:4739-1
ReleasePackageFixed inAdvisory
openSUSE Tumbleweed libsoup 3.8.1-1.1 openSUSE-SU-2026:12365-1
openSUSE Tumbleweed libsoup2 2.74.3-24.1 openSUSE-SU-2026:12084-1
openSUSE Leap 16.0 libsoup 3.6.6-160000.5.1 openSUSE-SU-2026:22181-1

Amazon Linux

ReleasePackageFixed inAdvisory
Amazon Linux 2023 libsoup +2 2.72.0-6.amzn2023.0.15 ALAS2023-2026-3154
Amazon Linux 2023 libsoup3 +2 3.7.2-1.amzn2023 ALAS2023-2026-3144
Amazon Linux 2 libsoup +1 2.56.0-6.amzn2.0.9 ALAS2-2026-3970

Azure Linux

ReleasePackageFixed inAdvisory
Azure Linux 3 libsoup No fix yet —

Advisories 15

References