An information disclosure vulnerability in the Qt Framework QWebSocket authentication handling of the Qt WebSockets module has been discovered and has been assigned the CVE id CVE-2026-114366.
Affected versions: from Qt 6.6.0 to Qt 6.8.9, from Qt 6.9.0 to Qt 6.11.2, Qt 6.12.0
Affected status unknown before Qt 6.6.0
Impact: Confidentiality (potential credentials leak)
CVSS 4.0 Score: 2.3 (Low)
Vector String: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/AU:N/RE:L/U:Green
Mitigation: Do not re-use the same QWebSocket instance for multiple connections.
Solution: Apply the following patch or update to Qt 6.8.10, Qt 6.11.3 or Qt 6.12.1 or later.
Patches:
dev: https://codereview.qt-project.org/c/qt/qtwebsockets/+/772273
6.12: https://codereview.qt-project.org/c/qt/qtwebsockets/+/774227 or https://download.qt.io/official_releases/qt/6.12/CVE-2026-114366-qtwebsockets-6.12-0001.diff
6.11: https://codereview.qt-project.org/c/qt/qtwebsockets/+/776326
6.8: https://codereview.qt-project.org/c/qt/tqtc-qtwebsockets/+/776328 or https://download.qt.io/archive/qt/6.8/CVE-2026-114366-qtwebsockets-6.8-0001.diff
