Proxy Auth Leakage in libSoup on Redirects
CVE-2026-1539 Published on January 28, 2026
Libsoup: libsoup: credential leakage via http redirects
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.
Vulnerability Analysis
CVE-2026-1539 can be exploited with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have a small impact on confidentiality, a small impact on integrity and availability.
Timeline
Reported to Red Hat.
Made public.
Weakness Type
Insertion of Sensitive Information Into Sent Data
The code transmits data to another actor, but a portion of the data includes sensitive information that should not be accessible to that actor. Sensitive information could include data that is sensitive in and of itself (such as credentials or private messages), or otherwise useful in the further exploitation of the system (such as internal file system structure).
Products Associated with CVE-2026-1539
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Affected Versions
Red Hat Enterprise Linux 10: Red Hat Enterprise Linux 6: Red Hat Enterprise Linux 7: Red Hat Enterprise Linux 8: Red Hat Enterprise Linux 9:Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.