Published May 22, 2026Sources checked Nov 11, 2026
3.3LOWCVSS out of 10
What this means
Review the available evidence
CVE-2026-39824 and is rated Low severity with a CVSS score of 3.3. 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: Nov 4, 2026
CBL-Mariner Releases
Vendor-listed releases
1.4.0-1
CISA KEVNot listedBased on the latest collected catalog
EPSS0.1%Estimated 30-day exploitation probability
Ransomware useNot markedCISA KEV ransomware field
Threat actors0Source-linked actor relationships
Overview
What is CVE-2026-39824?
NewNTUnicodeString does not check for string length overflow. When provided with a string that overflows the maximum size of a NTUnicodeString (a 16-bit number of bytes), it returns a truncated string rather than an error.