Published Jun 16, 2025Sources checked Nov 11, 2026
9.1CRITICALCVSS out of 10
What this means
Review the available evidence
CVE-2025-49794 and is rated Critical severity with a CVSS score of 9.1. 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: Aug 13, 2026
CBL-Mariner Releases
Vendor-listed releases
2.10.4-8
2.11.5-6
CISA KEVNot listedBased on the latest collected catalog
EPSS0.8%Estimated 30-day exploitation probability
Ransomware useNot markedCISA KEV ransomware field
Threat actors0Source-linked actor relationships
Overview
What is CVE-2025-49794?
A use-after-free vulnerability was found in libxml2. This issue occurs when parsing XPath elements under certain circumstances when the XML schematron has the <sch:name path="..."/> schema elements.
This flaw allows a malicious actor to craft a malicious XML document used as input for libxml, resulting in the program's crash using libxml or other possible undefined behaviors.