Vulnerability Report

CVE-2026-40399

Title: Stack-Based Buffer Overflow in Windows TCP/IP

Memory Corruption

Proof Of Concept

No public PoC currently indexed for CVE-2026-40399.

CWE Category CWE-121

Published Date May 12, 2026

Modified Date Jun 01, 2026

Exploit Status Not Found

Score 7.8 CVSS v3.1

Exploit Probability (EPSS)

0.33%

Vulnerability Summary

CVE-2026-40399: Concurrent execution using shared resource with improper synchronization ('race condition') in Windows TCP/IP allows an authorized attacker to elevate privileges locally.

Impacted Vendors

microsoft 13

Reference Links

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-40399

CVSS v3.1

Source Entity [email protected]

Severity HIGH

7.8

Attack Vector

LOCAL

Complexity

LOW

Privileges

N/A

Interaction

NONE

Confidentiality

N/A

Integrity

N/A

Availability

N/A

Scope

UNCHANGED

RAW VECTOR CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Associated Attack Patterns (CAPEC)

Total: Patterns

CVE-2026-40399 Exploits & PoCs (Proof Of Concept)

No public PoCs found in our database for this CVE.

June 01, 2026 MODIFIED

Vulnerability data updated via NVD.

May 15, 2026 MODIFIED

Vulnerability data updated via NVD.

May 13, 2026 MODIFIED

Vulnerability data updated via NVD.

May 12, 2026 MODIFIED

Vulnerability data updated via NVD.

Attack Vector Matrix

Access Vector LOCAL

Complexity LOW

Privileges N/A

Interaction NONE

CVSS Vector String


                                    CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected Stack

No specific products linked.