CVE-2026-5119
Redhat Enterprise Linux 10.0 … 9.0
Raw vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:L/A:NSummary
CVE-2026-5119 is a medium-severity Cleartext Transmission of Sensitive Information (CWE-319) vulnerability in Redhat Enterprise Linux. Its CVSS base score is 5.9 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique Network Sniffing (T1040); ranked at the 17th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified map to SC-8 (Transmission Confidentiality and Integrity) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-5119 is a vulnerability in libsoup, a library used for HTTP client/server capabilities in GNOME applications. The flaw occurs when establishing HTTPS tunnels through a configured HTTP proxy, where sensitive session cookies are transmitted in cleartext within the initial HTTP CONNECT request. This exposes the cookies to interception, as documented under CWE-319 (Cleartext Transmission of Sensitive Information). The issue carries a CVSS v3.1 base score of 5.9 (AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:L/A:N), indicating medium severity with high confidentiality impact.
A network-positioned attacker or a malicious HTTP proxy can exploit this vulnerability by intercepting the cleartext cookies in the CONNECT request. Exploitation requires the victim to interact with a site using libsoup via an HTTP proxy (user interaction required) and involves high attack complexity, typically in scenarios like man-in-the-middle on untrusted networks. Successful interception enables session hijacking or user impersonation, allowing attackers to compromise user sessions without privileges.
Mitigation details are available in related advisories, including the Red Hat security bulletin at https://access.redhat.com/security/cve/CVE-2026-5119, Red Hat Bugzilla entry at https://bugzilla.redhat.com/show_bug.cgi?id=2452932, and the GNOME libsoup GitLab issue at https://gitlab.gnome.org/GNOME/libsoup/-/issues/502, which likely cover patches and workarounds for affected versions.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-17062
Vulnerability Data
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,…
more
leading to potential session hijacking or user impersonation.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
SC-8 directly requires protecting confidentiality of transmitted information, which structurally eliminates cleartext transmission of sensitive data.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Encryption of data-in-transit directly prevents cleartext transmission while the control also addresses integrity and availability.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Specifying encryption and other security technology for network services prevents transmission of sensitive information in cleartext over potentially untrusted channels.
Mandating cryptographic protection and stronger authentication on public networks stops the transmission of plaintext sensitive information.
Specifying communications-security requirements and secure remote-access methods (including encryption expectations) prevents the transmission of sensitive data in cleartext over home or public networks.
Armoured conduits, electromagnetic shielding and locked enclosures make passive eavesdropping on unencrypted traffic traversing the cables more difficult, mitigating exposure of sensitive data in transit.