---
id: "CVE-2025-33073"
kind: "vulnerability"
aliases: ["CVE-2025-33073"]
title: "Improper access control in Windows SMB allows an authorized attacker to elevate privileges over a network"
severity: "high"
cvss: 8.8
epss: null
exploited: true
status: "open"
category: "infrastructure"
products: [{"name": "Microsoft Windows", "fixed": [], "affected": "", "ecosystem": "vendor"}, {"name": "microsoft windows 10 1507", "fixed": ["10.0.10240.21034"], "affected": "< 10.0.10240.21034", "ecosystem": "vendor"}, {"name": "microsoft windows 10 1607", "fixed": ["10.0.14393.8148"], "affected": "< 10.0.14393.8148", "ecosystem": "vendor"}, {"name": "microsoft windows 10 1809", "fixed": ["10.0.17763.7434"], "affected": "< 10.0.17763.7434", "ecosystem": "vendor"}, {"name": "microsoft windows 10 21h2", "fixed": ["10.0.19044.5965"], "affected": "< 10.0.19044.5965", "ecosystem": "vendor"}, {"name": "microsoft windows 10 22h2", "fixed": ["10.0.19045.5965"], "affected": "< 10.0.19045.5965", "ecosystem": "vendor"}, {"name": "microsoft windows 11 22h2", "fixed": ["10.0.22621.5472"], "affected": "< 10.0.22621.5472", "ecosystem": "vendor"}, {"name": "microsoft windows 11 23h2", "fixed": ["10.0.22631.5472"], "affected": "< 10.0.22631.5472", "ecosystem": "vendor"}, {"name": "microsoft windows 11 24h2", "fixed": ["10.0.26100.4270"], "affected": "< 10.0.26100.4270", "ecosystem": "vendor"}, {"name": "microsoft windows server 2008", "fixed": [], "affected": "", "ecosystem": "vendor"}, {"name": "microsoft windows server 2008", "fixed": [], "affected": "= r2", "ecosystem": "vendor"}, {"name": "microsoft windows server 2012", "fixed": [], "affected": "", "ecosystem": "vendor"}, {"name": "microsoft windows server 2012", "fixed": [], "affected": "= r2", "ecosystem": "vendor"}, {"name": "microsoft windows server 2016", "fixed": ["10.0.14393.8148"], "affected": "< 10.0.14393.8148", "ecosystem": "vendor"}, {"name": "microsoft windows server 2019", "fixed": ["10.0.17763.7434"], "affected": "< 10.0.17763.7434", "ecosystem": "vendor"}, {"name": "microsoft windows server 2022", "fixed": ["10.0.20348.3745"], "affected": "< 10.0.20348.3745", "ecosystem": "vendor"}, {"name": "microsoft windows server 2022 23h2", "fixed": ["10.0.25398.1665"], "affected": "< 10.0.25398.1665", "ecosystem": "vendor"}, {"name": "microsoft windows server 2025", "fixed": ["10.0.26100.4270"], "affected": "< 10.0.26100.4270", "ecosystem": "vendor"}]
ecosystems: ["vendor"]
tags: ["active-directory", "exploited", "infrastructure", "smb", "windows"]
not_affected_if: ["unknown"]
published_at: "2025-06-10T17:23:02+00:00"
first_seen_at: "2026-10-23T19:11:51+00:00"
updated_at: "2026-10-23T23:44:51+00:00"
sources: [{"source": "kev", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2025-33073", "first_seen_at": "2026-10-23T19:11:51+00:00"}, {"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-33073", "first_seen_at": "2026-10-23T23:44:51+00:00"}]
---

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

Windows SMB client has an improper access control flaw that lets an attacker escalate privileges on a Windows machine. A crafted script can make the victim machine connect back over SMB and authenticate to the attacker, which can expose credentials for relay or theft.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- vendor:Microsoft Windows affected ? fixed ?
- vendor:microsoft windows 10 1507 affected < 10.0.10240.21034 fixed 10.0.10240.21034
- vendor:microsoft windows 10 1607 affected < 10.0.14393.8148 fixed 10.0.14393.8148
- vendor:microsoft windows 10 1809 affected < 10.0.17763.7434 fixed 10.0.17763.7434
- vendor:microsoft windows 10 21h2 affected < 10.0.19044.5965 fixed 10.0.19044.5965
- vendor:microsoft windows 10 22h2 affected < 10.0.19045.5965 fixed 10.0.19045.5965
- vendor:microsoft windows 11 22h2 affected < 10.0.22621.5472 fixed 10.0.22621.5472
- vendor:microsoft windows 11 23h2 affected < 10.0.22631.5472 fixed 10.0.22631.5472
- vendor:microsoft windows 11 24h2 affected < 10.0.26100.4270 fixed 10.0.26100.4270
- vendor:microsoft windows server 2008 affected ? fixed ?
- vendor:microsoft windows server 2008 affected = r2 fixed ?
- vendor:microsoft windows server 2012 affected ? fixed ?
- vendor:microsoft windows server 2012 affected = r2 fixed ?
- vendor:microsoft windows server 2016 affected < 10.0.14393.8148 fixed 10.0.14393.8148
- vendor:microsoft windows server 2019 affected < 10.0.17763.7434 fixed 10.0.17763.7434
- vendor:microsoft windows server 2022 affected < 10.0.20348.3745 fixed 10.0.20348.3745
- vendor:microsoft windows server 2022 23h2 affected < 10.0.25398.1665 fixed 10.0.25398.1665
- vendor:microsoft windows server 2025 affected < 10.0.26100.4270 fixed 10.0.26100.4270

## Fix

Apply the Microsoft mitigations for CVE-2025-33073 and install the current Windows security update; the exact patch version is not in the sources.

## Timeline

- 2026-10-23T19:11:51+00:00 kev https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2025-33073
- 2026-10-23T23:44:51+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2025-33073

## From the sources

Microsoft Windows SMB Client contains an improper access control vulnerability that could allow for privilege escalation. An attacker could execute a specially crafted malicious script to coerce the victim machine to connect back to the attack system using SMB and authenticate.

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.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_