Windows NTLM
CVE-2025-21311 — Windows NTLM V1 Elevation of Privilege Vulnerability
Executive Summary
None
Overview
9.8
CVSS CRITICAL
Critical
MS Severity
Not Exploited
MS Exploit Status
Less Likely
MS Exploit Likelihood
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: 8.5
EPSS Score
0.02348
probability of exploitation in the next 30 days
0.81474 percentile - updated 2026-06-21
View on FIRST.org
Affected Products
5 affected products
| Product | KB Article | Severity | Impact | Restart Required |
|---|---|---|---|---|
| Windows 11 Version 24H2 for ARM64-based Systems | 5050009 (Security Update) |
Critical | Elevation of Privilege | Yes |
| Windows 11 Version 24H2 for x64-based Systems | 5050009 (Security Update) |
Critical | Elevation of Privilege | Yes |
| Windows Server 2022, 23H2 Edition (Server Core installation) | 5049984 (Security Update) |
Critical | Elevation of Privilege | Yes |
| Windows Server 2025 | 5050009 (Security Update) |
Critical | Elevation of Privilege | Yes |
| Windows Server 2025 (Server Core installation) | 5050009 (Security Update) |
Critical | Elevation of Privilege | Yes |
Patches
2 patches
| Article | Type | Restart |
|---|---|---|
5050009 |
Security Update | Yes |
5049984 |
Security Update | Yes |
Known Exploits
No known exploits have been linked for this CVE yet. When available, exploit references will be sourced from public repositories and may be unverified, incomplete, or non-functional. Always review code carefully before use in any environment.
Acknowledgments
References
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