CVE-2026-5119: Libsoup: libsoup: information disclosure via cleartext transmission of cookies during https tunnel establishment
A flaw was found in libsoup. When establishing HTTPS tunnels through a configured HTTP proxy, sensitive session cookies are transmitted in cleartext within the initial HTTP CONNECT request. A network-positioned attacker or a malicious HTTP proxy can intercept these cookies, leading to potential session hijacking or user impersonation.
Other sources
Cleartext Transmission of Sensitive Information has been reported in libsoup’s HTTP CONNECT handling. When establishing HTTPS tunnels via soupsession.c::tunnelconnect(), cookies (including potentially sensitive session cookies) are sent in cleartext within the initial HTTP CONNECT request to the configured proxy. A network-positioned attacker or malicious HTTP proxy can intercept or observe these cookies and leverage them for session hijacking or user impersonation.
— Red Hat
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2026-5119?
CVE-2026-5119 has a medium severity rating due to the potential for information disclosure.
How do I fix CVE-2026-5119?
To fix CVE-2026-5119, update to the latest version of libsoup that addresses this vulnerability.
What is the impact of CVE-2026-5119 on affected systems?
CVE-2026-5119 can lead to the exposure of sensitive session cookies during HTTPS tunnel establishment through an HTTP proxy.
Which software is affected by CVE-2026-5119?
CVE-2026-5119 affects the GNOME libsoup library.
Can CVE-2026-5119 be exploited remotely?
Yes, CVE-2026-5119 can be exploited remotely, enabling attackers to capture sensitive cookies.