[Announce] Security advisory: Qt Network

[List for announcements regarding Qt releases and development]

Qt Network incorrectly parses the strict-transport-security (HSTS) header, allowing unencrypted connections to be established, even when explicitly prohibited by the server. This happens if the case used for this header does not matching directly. Unencrypted connections are susceptible to man-in-the-middle attacks. Those connections could be established by using URLs with the http instead of the https scheme. With HSTS, the https scheme must be used regardless.

Solution: Apply the following patch or update to Qt 5.15.14, Qt 6.2.9 or Qt 6.5.1
Patches:
dev: https://codereview.qt-project.org/c/qt/qtbase/+/477560
Qt 6.5: https://codereview.qt-project.org/c/qt/qtbase/+/476494 or https://download.qt.io/official_releases/qt/6.5/CVE-2023-32762-qtbase-6.5.diff
Qt 6.2: https://download.qt.io/official_releases/qt/6.2/CVE-2023-32762-qtbase-6.2.diff
Qt 5.15: https://download.qt.io/official_releases/qt/5.15/CVE-2023-32762-qtbase-5.15.diff

Kind regards,
Andy
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Andy Shaw
Director, Technical Customer Success 
The Qt Company