Overview
What is CVE-2026-4224?
When an Expat parser with a registered ElementDeclHandler parses an inline document type definition containing a deeply nested content model a C stack overflow occurs.
CVE intelligence
CVE-2026-4224
Vulnerability intelligence
7.5HIGHCVSS out of 10
What this means
Review the available evidence
CVE-2026-4224 and is rated High severity with a CVSS score of 7.5. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.
CISA KEVNot listedBased on the latest collected catalog
EPSS0.7%Estimated 30-day exploitation probability
Ransomware useNot markedCISA KEV ransomware field
Threat actors0Source-linked actor relationships