Proxy-Authorization Header Exposure in libsoup Causes Credential Leak

Publication date: 2026-01-28

Last updated on: 2026-03-25

Assigner: Red Hat, Inc.

Description

A flaw was found in the libsoup HTTP library that can cause proxy authentication credentials to be sent to unintended destinations. When handling HTTP redirects, libsoup removes the Authorization header but does not remove the Proxy-Authorization header if the request is redirected to a different host. As a result, sensitive proxy credentials may be leaked to third-party servers. Applications using libsoup for HTTP communication may unintentionally expose proxy authentication data.

CVSS Scores

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Meta Information

Published

2026-01-28

Last Modified

2026-03-25

Generated

2026-07-06

AI Q&A

2026-01-29

EPSS Evaluated

2026-07-05

NVD

CVE-2026-1539

EUVD

EUVD-2026-4889

Affected Vendors & Products

Vendor	Product	Version / Range
redhat	enterprise_linux	7.0
redhat	enterprise_linux	6.0
redhat	enterprise_linux	8.0
redhat	enterprise_linux	9.0
redhat	enterprise_linux	10.0
gnome	libsoup	*

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-201	The code transmits data to another actor, but a portion of the data includes sensitive information that should not be accessible to that actor.

Attack-Flow Graph

Executive Summary

This vulnerability is a flaw in the libsoup HTTP library where proxy authentication credentials can be sent to unintended destinations. Specifically, when handling HTTP redirects, libsoup removes the Authorization header but fails to remove the Proxy-Authorization header if the request is redirected to a different host. This can cause sensitive proxy credentials to be leaked to third-party servers.

Impact Analysis

This vulnerability can lead to the unintended exposure of sensitive proxy authentication credentials to third-party servers. If you use applications that rely on libsoup for HTTP communication, your proxy credentials might be leaked during HTTP redirects, potentially allowing unauthorized parties to access your proxy or network resources.

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