CVE-2021-31956

Microsoft Windows NTFS Privilege Escalation Vulnerability

IN CISA KEV

Microsoft Windows New Technology File System (NTFS) contains an unspecified vulnerability that allows attackers to escalate privileges via a specially crafted application.

Vendor: Microsoft
Product: Windows
CVSS: No score recorded (no NVD record loaded for this entry)
CWE: CWE-191, CWE-787
Published: Not recorded
NVD modified: Not recorded

CISA KEV

Date added: 2021-11-03
Due date: 2021-11-17
Ransomware use: Unknown
Required action: Apply updates per vendor instructions.

EPSS

22.3% chance of exploitation in the next 30 days (percentile 97th)

FIRST EPSS, updated 17 Oct 2026. About EPSS

CVSS is severity, EPSS is likelihood, KEV means already exploited. EPSS is a statistical probability, not a certainty: a low score does not make a bug safe, and a high one does not prove it is being exploited.

Data last updated 18 Oct 2026. Sources: NVD API 2.0, CISA KEV catalog, FIRST EPSS. Links: NVD, CISA KEV. Metadata only. ThreatWire does not host exploit code.