---
title: "CVE-2025-33073: Microsoft Windows SMB Client Improper Access Control Vulnerability"
url: https://erroneo.us/security/cve/CVE-2025-33073/
description: "CVE-2025-33073 (Microsoft Windows): Exploited in the wild (CISA KEV). Improper access control in Windows SMB allows an authorized attacker to elevate…"
type: vulnerability-record
section: "Security Digest"
date_published: 2025-06-10
date_modified: 2026-02-26
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2025-33073"
kev: true
cvss: 8.8
epss: 0.82699
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2025-33073: Microsoft Windows SMB Client Improper Access Control Vulnerability

**Signal:** Exploited: patch now if you run it. CISA has confirmed exploitation in the wild. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- Yes, if you run Microsoft Windows. CISA added this CVE to its Known Exploited Vulnerabilities catalog on 2025-10-20, which means there is reliable evidence of exploitation in the wild. US federal agencies must remediate by 2025-11-10 ; treat that as the outer limit, not the target.
- EPSS 82.7% , percentile 99.7: FIRST’s model estimates a 82.7% chance of exploitation activity in the next 30 days, higher than 99.7% of all scored CVEs (very high). EPSS is a probability, not a verdict.
- Needs an account (low (any account)). Exposure depends on who can log in.

## What it is

Improper access control in Windows SMB allows an authorized attacker to elevate privileges over a network.

## Affected products (CVE record)

- Microsoft Windows 10 Version 1507: 10.0.10240.0 < 10.0.10240.21034
- Microsoft Windows 10 Version 1607: 10.0.14393.0 < 10.0.14393.8148
- Microsoft Windows 10 Version 1809: 10.0.17763.0 < 10.0.17763.7434
- Microsoft Windows 10 Version 21H2: 10.0.19044.0 < 10.0.19044.5965
- Microsoft Windows 10 Version 22H2: 10.0.19045.0 < 10.0.19045.5965
- Microsoft Windows 11 version 22H2: 10.0.22621.0 < 10.0.22621.5472
- Microsoft Windows 11 version 22H3: 10.0.22631.0 < 10.0.22631.5472
- Microsoft Windows 11 Version 23H2: 10.0.22631.0 < 10.0.22631.5472
- Microsoft Windows 11 Version 24H2: 10.0.26100.0 < 10.0.26100.4349
- Microsoft Windows Server 2008 R2 Service Pack 1: 6.1.7601.0 < 6.1.7601.27769

## Severity

- microsoft CVSS 3.1: 8.8 `CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C`

## Exploitation

- CISA KEV: added 2025-10-20; federal due date 2025-11-10. Known ransomware use: Unknown.
- CISA required action: 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 SSVC assessment: exploitation active , automatable no , technical impact total .
- FIRST EPSS (model of 2026-10-21): 82.70% probability of exploitation activity in the next 30 days; percentile 99.7.

## Sources

- [Windows SMB Client Elevation of Privilege Vulnerability](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-33073)
- [Listed in CISA KEV notes (msrc.microsoft.com)](https://msrc.microsoft.com/update-guide/en-US/advisory/CVE-2025-33073)
- [CVE.org record CVE-2025-33073](https://www.cve.org/CVERecord?id=CVE-2025-33073)
- [NVD entry CVE-2025-33073](https://nvd.nist.gov/vuln/detail/CVE-2025-33073)
- [CISA Known Exploited Vulnerabilities catalog entry](https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-33073)
- [vicarius.io](https://www.vicarius.io/vsociety/posts/cve-2025-33073-detection-script-improper-access-control-in-windows-smb-affects-microsoft-products)
- [vicarius.io](https://www.vicarius.io/vsociety/posts/cve-2025-33073-mitigation-script-improper-access-control-in-windows-smb-affects-microsoft-products)

---
Source page: https://erroneo.us/security/cve/CVE-2025-33073/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt