PT-2026-40148 · Microsoft · Windows Kernel+1

Andrew Fasano + 3 · CVE-2026-33841 · Published 2026-05-12 · Updated 2026-06-17

Positive Technologies (AI Summary)

CVSS v3.1

7.8

High

Base vector

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

Name of the Vulnerable Software and Affected Versions Microsoft Windows versions prior to Server 2025

Description A heap-based buffer overflow in the Windows Kernel allows an authorized local attacker to elevate their privileges. A buffer overflow occurs when a program writes more data to a memory block (the buffer) than it is allocated to hold, potentially overwriting adjacent memory.

Recommendations Update to a version released after the May 2026 patch cycle.

Fix

DoS

Heap Based Buffer Overflow

Weakness Enumeration

CWE-122

Related Identifiers

BDU:2026-06739

CVE-2026-33841

Affected Products

Windows

Windows Kernel

References · 9

• https://safe-surf.ru/specialists/bulletins-nkcki/731799 · Security Note
• https://bdu.fstec.ru/vul/2026-06739 · Security Note
• https://msrc.microsoft.com/update-guide/en-US/advisory/CVE-2026-33841 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-33841 · Security Note
• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-33841 · Vendor Advisory
• http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2026-33841 · Security Note
• https://t.me/cveNotify/169939 · Telegram Post
• https://twitter.com/f1tym1/status/2055171275182539209 · Twitter Post
• https://twitter.com/windowsforum/status/2054260499634696585 · Twitter Post