An out-of-bounds read vulnerability in the Qt Framework CBOR parsing functionality (QCborValue::fromCbor()) of the Qt Core module has been discovered and has been assigned the CVE id CVE-2026-107157.
Affected versions: from Qt 5.12.0 to Qt 6.8.8, from Qt 6.9.0 to Qt 6.11.2 (64-bit platforms only)
Impact: Processing specially crafted input through the affected API may cause the application to crash and could potentially lead to information disclosure.
CVSS 4.0 Score: 2.0 / LOW
Vector String: CVSS:4.0/AV:L/AC:H/AT:N/PR:N/UI:P/VC:H/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/RE:L/U:Amber
Mitigation: Use the QByteArray overload of QCborValue::fromCbor() instead of the overloads that take a pointer and a size. Also validate and limit the size of untrusted CBOR input before parsing it.
Solution: Apply the patches below, or update to Qt 6.8.9, Qt 6.11.3, Qt 6.12.0 or later.
Patches:
dev: https://codereview.qt-project.org/c/qt/qtbase/+/745719
Qt 6.11: https://codereview.qt-project.org/c/qt/qtbase/+/746659 or https://download.qt.io/official_releases/qt/6.11/CVE-2026-107157-qtbase-6.11.diff
Qt 6.8: https://codereview.qt-project.org/c/qt/tqtc-qtbase/+/746714 or https://download.qt.io/archive/qt/6.8/CVE-2026-107157-qtbase-6.8.diff
