OnlyPatch
Windows SMB

CVE-2025-55234 — Windows SMB Elevation of Privilege Vulnerability

Important CVSS 9.8 EPSS 0.18834 📢 Publicly disclosed 2025-09 archive

Executive Summary

SMB Server might be susceptible to relay attacks depending on the configuration. An attacker who successfully exploited these vulnerabilities could perform relay attacks and make the users subject to elevation of privilege attacks. The SMB Server already supports mechanisms for hardening against relay attacks: Microsoft is releasing this CVE to provide customers with audit capabilities to help them to assess their environment and to identify any potential device or software incompatibility issues before deploying SMB Server hardening measures that protect against relay attacks. If you have not already enabled SMB Server hardening measures, we advise customers to take the following actions to be protected from these relay attacks:

Overview

9.8
CVSS CRITICAL
Important
MS Severity
Not Exploited
MS Exploit Status
More Likely
MS Exploit Likelihood
Category Elevation of Privilege
Weakness CWE-287: Improper Authentication
Released Sep 9 2025
Last Updated Sep 9 2025
Publicly Disclosed Yes
CISA KEV Not Listed
Known Exploits None Known
EPSS Score 0.18834 — 0.96984 percentile
NVD CVSS 9.8 CRITICAL — differs from MSRC

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
ATTACK VECTOR
Network
ATTACK COMPLEXITY
Low
PRIVILEGES REQUIRED
None
USER INTERACTION
None
SCOPE
Unchanged
CONFIDENTIALITY
High
INTEGRITY
High
AVAILABILITY
High
EXPLOIT CODE MATURITY
Unproven
REMEDIATION LEVEL
Official Fix
REPORT CONFIDENCE
Confirmed
Temporal Score: 7.7

EPSS Score

0.18834
probability of exploitation in the next 30 days
0.96984 percentile - updated 2026-07-25
View on FIRST.org

Affected Products

25 affected products
Product KB Article Severity Impact Restart Required
Windows 10 for 32-bit Systems 5065430 (Security Update) Important Elevation of Privilege Yes
Windows 10 for x64-based Systems 5065430 (Security Update) Important Elevation of Privilege Yes
Windows 10 Version 1607 for 32-bit Systems 5065427 (Security Update) Important Elevation of Privilege Yes
Windows 10 Version 1607 for x64-based Systems 5065427 (Security Update) Important Elevation of Privilege Yes
Windows 10 Version 1809 for 32-bit Systems 5065428 (Security Update) Important Elevation of Privilege Yes
Windows 10 Version 1809 for x64-based Systems 5065428 (Security Update) Important Elevation of Privilege Yes
Windows 10 Version 21H2 for 32-bit Systems 5065429 (Security Update) Important Elevation of Privilege Yes
Windows 10 Version 21H2 for ARM64-based Systems 5065429 (Security Update) Important Elevation of Privilege Yes
Windows 10 Version 21H2 for x64-based Systems 5065429 (Security Update) Important Elevation of Privilege Yes
Windows 10 Version 22H2 for 32-bit Systems 5065429 (Security Update) Important Elevation of Privilege Yes
Windows 10 Version 22H2 for ARM64-based Systems 5065429 (Security Update) Important Elevation of Privilege Yes
Windows 10 Version 22H2 for x64-based Systems 5065429 (Security Update) Important Elevation of Privilege Yes
Windows 11 Version 22H2 for ARM64-based Systems 5065431 (Security Update) Important Elevation of Privilege Yes
Windows 11 Version 22H2 for x64-based Systems 5065431 (Security Update) Important Elevation of Privilege Yes
Windows 11 Version 23H2 for ARM64-based Systems 5065431 (Security Update) Important Elevation of Privilege Yes
Windows 11 Version 23H2 for x64-based Systems 5065431 (Security Update) Important Elevation of Privilege Yes
Windows 11 Version 24H2 for ARM64-based Systems 5065426 (Security Update) 5065474 (SecurityHotpatchUpdate) Important Elevation of Privilege 5063878 5064010 Base: 8.8 Temporal: 7.7 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C 10.0.26100.6584 10.0.26100.6508 Yes None Windows 11 Version 24H2 for x64-based Systems 5065426 (Security Update) 5065474 (SecurityHotpatchUpdate) Important Elevation of Privilege 5063878 5064010 Base: 8.8 Temporal: 7.7 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C 10.0.26100.6584 10.0.26100.6508 Yes None Windows Server 2008 for 32-bit Systems Service Pack 2 5065508 (Monthly Rollup) 5065511 (Security Only) Important Elevation of Privilege 5063888 Base: 8.8 Temporal: 7.7 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C 6.0.6003.23529 Yes None Windows Server 2008 for 32-bit Systems Service Pack 2 (Server Core installation) 5065508 (Monthly Rollup) 5065511 (Security Only) Important Elevation of Privilege 5063888 Base: 8.8 Temporal: 7.7 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C 6.0.6003.23529 Yes None Windows Server 2008 for x64-based Systems Service Pack 2 5065508 (Monthly Rollup) 5065511 (Security Only) Important Elevation of Privilege 5063888 Base: 8.8 Temporal: 7.7 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C 6.0.6003.23529 Yes None Windows Server 2008 for x64-based Systems Service Pack 2 (Server Core installation) 5065508 (Monthly Rollup) 5065511 (Security Only) Important Elevation of Privilege 5063888 Base: 8.8 Temporal: 7.7 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C 6.0.6003.23529 Yes None Windows Server 2008 R2 for x64-based Systems Service Pack 1 5065468 (Monthly Rollup) 5065510 (Security Only) Important Elevation of Privilege 5063947 Base: 8.8 Temporal: 7.7 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C 6.1.7601.27929 Yes None Windows Server 2008 R2 for x64-based Systems Service Pack 1 (Server Core installation) 5065468 (Monthly Rollup) 5065510 (Security Only) Important Elevation of Privilege 5063947 Base: 8.8 Temporal: 7.7 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C 6.1.7601.27929 Yes None Windows Server 2012 5065509 (Monthly Rollup) Important Elevation of Privilege Yes
Windows Server 2012 (Server Core installation) 5065509 (Monthly Rollup) Important Elevation of Privilege Yes
Windows Server 2012 R2 5065507 (Monthly Rollup) Important Elevation of Privilege Yes
Windows Server 2012 R2 (Server Core installation) 5065507 (Monthly Rollup) Important Elevation of Privilege Yes
Windows Server 2016 5065427 (Security Update) Important Elevation of Privilege Yes
Windows Server 2016 (Server Core installation) 5065427 (Security Update) Important Elevation of Privilege Yes
Windows Server 2019 5065428 (Security Update) Important Elevation of Privilege Yes
Windows Server 2019 (Server Core installation) 5065428 (Security Update) Important Elevation of Privilege Yes
Windows Server 2022 5065432 (Security Update) 5065306 (SecurityHotpatchUpdate) Important Elevation of Privilege 5063880 5063812 Base: 8.8 Temporal: 7.7 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C 10.0.20348.4171 10.0.20348.4106 Yes None Windows Server 2022 (Server Core installation) 5065432 (Security Update) 5065306 (SecurityHotpatchUpdate) Important Elevation of Privilege 5063880 5063812 Base: 8.8 Temporal: 7.7 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C 10.0.20348.4171 10.0.20348.4106 Yes None Windows Server 2022, 23H2 Edition (Server Core installation) 5065425 (Security Update) Important Elevation of Privilege Yes

Patches

8 patches
Article Type Restart
5065430 Security Update Yes
5065427 Security Update Yes
5065428 Security Update Yes
5065429 Security Update Yes
5065431 Security Update Yes
5065509 Monthly Rollup Yes
5065507 Monthly Rollup Yes
5065425 Security Update Yes

Known Exploits

Acknowledgments

Anonymous

On This Page