Published Sep 23, 2026Sources checked Oct 21, 2026
2.3LOWCVSS out of 10
What this means
Review the available evidence
CVE-2026-78253 and is rated Low severity with a CVSS score of 2.3. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.
What to do next
Remediation and response
Microsoft Security Response Center guidance
Vendor revision: Oct 14, 2026
Release Notes
Vendor-listed releases
6.6.3-7
CISA KEVNot listedBased on the latest collected catalog
EPSS0.3%Estimated 30-day exploitation probability
Ransomware useNot markedCISA KEV ransomware field
Threat actors0Source-linked actor relationships
Overview
What is CVE-2026-78253?
Uncontrolled recursion in QXmlStreamReader::readElementText() in Qt Group Qt allows attackers to cause a denial of service (application crash via stack exhaustion) via a crafted XML document.