Microsoft Windows SMB Client Improper Access Control Vulnerability
Improper access control in Windows SMB allows an authorized attacker to elevate privileges over a network.
What happened
Improper access control in Windows SMB allows an authorized attacker to elevate privileges over a network.
CISA lists it as exploited, added 20 Oct 2025.
Does it affect you
Names Microsoft Windows Server. Enter the product and version you run to place it against the affected range the vendor published.
What to do
- Follow the vendor advisory for the fixed release and any interim mitigation.
msrc.microsoft.com - Follow the vendor advisory for the fixed release and any interim mitigation.
vicarius.io - Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
cisa.gov
CISA’s notes for this entry:
Affected, as published to NVD
- ms-winserver
- Microsoft Windows Server: everything below 10.0.14393.8148
The record
- NVD status
- Analyzed
- Published
- 10 Jun 2025, last modified 17 Jun 2026 (NVD)
- Severity
- CVSS 3.1 base score 8.8, High — computed here from the vector; NVD states 8.8.
- Vector
- CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Weakness
- CWE-284 Improper Access Control (NVD; names by MITRE)
- Exploitation
- Listed in CISA’s Known Exploited Vulnerabilities catalogue since 20 Oct 2025; federal remediation due 10 Nov 2025. CISA entry
- Exploit probability
- EPSS 82.7%, 100th percentile — FIRST, scored 23 Oct 2026. FIRST EPSS
- Vendor
- Microsoft · Windows (CISA)
References on the NVD record
- msrc.microsoft.com/update-guide/vulnerability/CVE-2025-33073Vendor Advisory
- vicarius.io/vsociety/posts/cve-2025-33073-mitigation-script-improper-access-control-in-windows-smb-affects-microsoft-productsMitigationThird Party Advisory
- vicarius.io/vsociety/posts/cve-2025-33073-detection-script-improper-access-control-in-windows-smb-affects-microsoft-productsThird Party Advisory
- cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-33073US Government Resource
Sources
The verdict above is computed from the products and versions you entered and the affected ranges the vendor published to NVD. It does not inspect your environment, and this site never reports a product as unaffected: why.