HOMEVULNERABILITIESCVE-2026-40402
CRITICAL

CVE-2026-40402

CWE-416Published: May 12, 2026· Updated: May 15, 2026

9.3
CVSS v3.1
EPSS:0.04%probability of exploitation in 30 daysPercentile:13.6th

Official Description

Use after free in Windows Hyper-V allows an unauthorized attacker to elevate privileges locally.

NVD Source

Technical Analysis

CVE-2026-40402 requires local access, meaning attackers must already have a foothold on the target system.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 9.3.

The vulnerability has a "Changed" scope, meaning successful exploitation can impact components beyond the vulnerable component itself — such as the host operating system or adjacent services.

From a weakness classification perspective (CWE-416): Use-after-free vulnerabilities involve accessing memory after it has been freed, often enabling arbitrary code execution.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorLocal
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeChanged
Impact
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

Affected Vendors & Products

Microsoft2 products
windows 11 23h2windows server 2022
Source: NVD CPE · 2 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
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Official Patches & Advisories

All References (1)

Quick Facts

CVE IDCVE-2026-40402
CVSS Score9.3 / 10
SeverityCRITICAL
WeaknessCWE-416
CISA KEVNo
EPSS (30d)0.04%
Affected1 vendor
PublishedMay 12, 2026

Related CVEs (CWE-416)

Recommended Actions

  • Apply vendor patches immediately
  • Monitor CVE-2026-40402 in threat intel feeds
  • Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.