[Announce] Security advisory: CVE-2026-19248: Unbounded recursion vulnerability in the QDomNode destructor of Qt XML impacts Qt

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Unbounded destructor recursion in the QDomNode destructor of Qt XML has been discovered and has been assigned the CVE id CVE-2026-19248.
[cid:e91aec8f-862e-4738-877a-8bde534e53e5]
Affected versions: from Qt 2.2.0 to Qt 6.8.8, from Qt 6.9.0 to Qt 6.11.1

Impact:  Applications that parse untrusted or externally-supplied XML using the QDom classes (e.g. QDomDocument) may crash due to a denial-of-service condition. This may potentially be triggered remotely if the XML originates from an untrusted network source.

CVSS 4.0 Score: 7.1 (High)

Vector String: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/AU:N/R:U/V:D/RE:L

Mitigation:
- Use QXmlStreamReader / QXmlStreamWriter instead of QDomDocument.
- Limit the depth of the XML being parsed through other means.
- Increase the stack size from the default.
- Build Qt in a mode that uses less stack per frame than the default compiler settings.

Solution:  Update to Qt 6.8.9, Qt 6.11.2, or later. Users remaining on the now-closed Qt 6.10 branch should apply the Qt 6.10 patch.

Patches:
 dev: https://codereview.qt-project.org/c/qt/qtbase/+/740427
Qt 6.8: https://codereview.qt-project.org/c/qt/tqtc-qtbase/+/753360
or https://download.qt.io/official_releases/qt/6.8/CVE-2026-19248-qtbase-6.8.diff
Qt 6.10: https://codereview.qt-project.org/c/qt/qtbase/+/759017
or https://download.qt.io/official_releases/qt/6.10/CVE-2026-19248-qtbase-6.10.diff
Qt 6.11: https://codereview.qt-project.org/c/qt/qtbase/+/752665
or https://download.qt.io/official_releases/qt/6.11/CVE-2026-19248-qtbase-6.11.diff


Tero Pelkonen
Qt Group

Confidential
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