CVE-2026-66339: Insertion of Sensitive Information Into Sent Data in Red Hat Red Hat Enterprise Linux 10
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.
AI Analysis
Technical Summary
CVE-2026-66339 describes a flaw in libsoup where, after a CONNECT tunnel is established through an HTTP proxy, the Proxy-Authorization header is erroneously attached to subsequent HTTPS requests sent through the tunnel to the destination server. This results in the destination server receiving proxy credentials, leading to sensitive information disclosure. The vulnerability affects Red Hat Enterprise Linux 10. No explicit affected versions or patch information are provided in the advisory.
Potential Impact
The vulnerability allows the destination server to capture proxy credentials that should remain confidential. This leads to information disclosure but does not affect integrity or availability. The CVSS score of 6.5 reflects a medium severity impact with network attack vector, low attack complexity, no privileges required, and user interaction needed.
Mitigation Recommendations
Patch status is not yet confirmed — check the Red Hat advisory at https://access.redhat.com/security/cve/CVE-2026-66339 for current remediation guidance. No official fix or workaround is explicitly stated in the provided data. Users should monitor the vendor advisory for updates and apply any patches or mitigations once available.
CVE-2026-66339: Insertion of Sensitive Information Into Sent Data in Red Hat Red Hat Enterprise Linux 10
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.
CVSS v3.1
Score 6.5medium
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-66339 describes a flaw in libsoup where, after a CONNECT tunnel is established through an HTTP proxy, the Proxy-Authorization header is erroneously attached to subsequent HTTPS requests sent through the tunnel to the destination server. This results in the destination server receiving proxy credentials, leading to sensitive information disclosure. The vulnerability affects Red Hat Enterprise Linux 10. No explicit affected versions or patch information are provided in the advisory.
Potential Impact
The vulnerability allows the destination server to capture proxy credentials that should remain confidential. This leads to information disclosure but does not affect integrity or availability. The CVSS score of 6.5 reflects a medium severity impact with network attack vector, low attack complexity, no privileges required, and user interaction needed.
Mitigation Recommendations
Patch status is not yet confirmed — check the Red Hat advisory at https://access.redhat.com/security/cve/CVE-2026-66339 for current remediation guidance. No official fix or workaround is explicitly stated in the provided data. Users should monitor the vendor advisory for updates and apply any patches or mitigations once available.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- redhat
- Date Reserved
- 2026-07-24T22:32:18.748Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
- Vendor Advisory Urls
- [{"url":"https://access.redhat.com/security/cve/CVE-2026-66339","vendor":"Red Hat"}]
Threat ID: 6a63f3c69c2644c7f8bc9756
Added to database: 07/24/2026, 23:22:46 UTC
Last enriched: 08/01/2026, 20:42:00 UTC
Last updated: 09/07/2026, 22:52:14 UTC
Views: 106
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