Important CVSS 7.8 EPSS 0.0031 2026-05 archive

Executive Summary

Heap-based buffer overflow in Windows Kernel allows an authorized attacker to elevate privileges locally.

Overview

7.8
CVSS HIGH
Important
MS Severity
Not Exploited
MS Exploit Status
More Likely
MS Exploit Likelihood
Category Elevation of Privilege
Released May 12 2026
Last Updated May 12 2026
Publicly Disclosed No
CISA KEV Not Listed
Known Exploits None Known
EPSS Score 0.0031 — 0.22526 percentile
NVD CVSS 7.8 HIGH — matches MSRC

CVSS Vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
ATTACK VECTOR
Local
ATTACK COMPLEXITY
Low
PRIVILEGES REQUIRED
Low
USER INTERACTION
None
SCOPE
Unchanged
CONFIDENTIALITY
High
INTEGRITY
High
AVAILABILITY
High
EXPLOIT CODE MATURITY
Unproven
REMEDIATION LEVEL
Official Fix
REPORT CONFIDENCE
Confirmed
Temporal Score: 6.8

EPSS Score

0.0031
probability of exploitation in the next 30 days
0.22526 percentile - updated 2026-06-21
View on FIRST.org

Affected Products

11 affected products
Product KB Article Severity Impact Restart Required
Windows 10 Version 21H2 for 32-bit Systems 5087544 (Security Update) Important Elevation of Privilege Yes
Windows 10 Version 21H2 for ARM64-based Systems 5087544 (Security Update) Important Elevation of Privilege Yes
Windows 10 Version 21H2 for x64-based Systems 5087544 (Security Update) Important Elevation of Privilege Yes
Windows 10 Version 22H2 for 32-bit Systems 5094127 (Security Update) Important Elevation of Privilege Yes
Windows 10 Version 22H2 for ARM64-based Systems 5094127 (Security Update) Important Elevation of Privilege Yes
Windows 10 Version 22H2 for x64-based Systems 5094127 (Security Update) Important Elevation of Privilege Yes
Windows 11 Version 23H2 for ARM64-based Systems 5087420 (Security Update) Important Elevation of Privilege Yes
Windows 11 Version 23H2 for x64-based Systems 5093998 (Security Update) Important Elevation of Privilege Yes
Windows 11 Version 24H2 for ARM64-based Systems 5089549 (Security Update) 5089466 (Security Hotpatch Update) Important Elevation of Privilege 5082063 Base: 7.8 Temporal: 6.8 Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C 10.0.26100.8457 10.0.26100.8390 Yes None Windows 11 Version 24H2 for x64-based Systems 5089549 (Security Update) 5089466 (Security Hotpatch Update) Important Elevation of Privilege 5082063 Base: 7.8 Temporal: 6.8 Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C 10.0.26100.8457 10.0.26100.8390 Yes None Windows 11 Version 25H2 for ARM64-based Systems 5089549 (Security Update) 5089466 (Security Hotpatch Update) Important Elevation of Privilege 5083769 Base: 7.8 Temporal: 6.8 Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C 10.0.26200.8457 10.0.26200.8390 Yes None Windows 11 Version 25H2 for x64-based Systems 5089549 (Security Update) 5089466 (Security Hotpatch Update) Important Elevation of Privilege 5083769 Base: 7.8 Temporal: 6.8 Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C 10.0.26200.8457 10.0.26200.8390 Yes None Windows 11 Version 26H1 for ARM64-based Systems 5089548 (Security Update) Important Elevation of Privilege Yes
Windows 11 version 26H1 for x64-based Systems 5089548 (Security Update) Important Elevation of Privilege Yes
Windows Server 2022 5087545 (Security Update) 5087424 (Security Hotpatch Update) Important Elevation of Privilege 5082142 Base: 7.8 Temporal: 6.8 Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C 10.0.20348.5139 10.0.20348.5074 Yes None Windows Server 2022 (Server Core installation) 5087545 (Security Update) 5087424 (Security Hotpatch Update) Important Elevation of Privilege 5082142 Base: 7.8 Temporal: 6.8 Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C 10.0.20348.5139 10.0.20348.5074 Yes None Windows Server 2022, 23H2 Edition (Server Core installation) 5087541 (Security Update) Important Elevation of Privilege Yes

Patches

6 patches
Article Type Restart
5087544 Security Update Yes
5094127 Security Update Yes
5087420 Security Update Yes
5093998 Security Update Yes
5089548 Security Update Yes
5087541 Security Update Yes

Known Exploits

Acknowledgments

Minjea Park, Kentaro Kawane with GMO Cybersecurity by Ierae, Inc., Anonymous, NIST Center for AI Standards and Innovation, Minwoo Jeong (P1nkjelly), r0keb