Microsoft Windows up to Server 2025 Setup Files Cleanup untrusted search path

CVSS Meta Temp Score
CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.
Current Exploit Price (≈)
Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.
CTI Interest Score
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
6.8$5k-$25k0.00-

Summaryinfo

A vulnerability was found in Microsoft Windows. It has been rated as critical. This impacts an unknown function of the component Setup Files Cleanup. Performing a manipulation results in untrusted search path. This vulnerability is known as CVE-2026-83509. Attacking locally is a requirement. No exploit is available. Applying a patch is the recommended action to fix this issue.

Detailsinfo

A vulnerability, which was classified as critical, was found in Microsoft Windows. This affects an unknown function of the component Setup Files Cleanup. The manipulation with an unknown input leads to a untrusted search path vulnerability. CWE is classifying the issue as CWE-426. The product searches for critical resources using an externally-supplied search path that can point to resources that are not under the product's direct control. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

Untrusted search path in Windows Setup Files Cleanup allows an authorized attacker to elevate privileges locally.

The advisory is shared at msrc.microsoft.com. This vulnerability is uniquely identified as CVE-2026-83509 since 08/31/2026. The exploitability is told to be difficult. An attack has to be approached locally. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 10/14/2026). MITRE ATT&CK project uses the attack technique T1574 for this issue.

Applying a patch is able to eliminate this problem.

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.0
VulDB Meta Temp Score: 6.8

VulDB Base Score: 7.0
VulDB Temp Score: 6.7
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 7.0
CNA Vector (microsoft): 🔒

CVSSv2info

AVACAuCIA
💳💳💳💳💳💳
💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock

VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Untrusted search path
CWE: CWE-426
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: No

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

0-DayUnlockUnlockUnlockUnlock
TodayUnlockUnlockUnlockUnlock

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Patch
Status: 🔍

0-Day Time: 🔒

Timelineinfo

08/31/2026 CVE reserved
10/14/2026 +44 days Advisory disclosed
10/14/2026 +0 days VulDB entry created
10/14/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: microsoft.com
Product: microsoft.com

Advisory: msrc.microsoft.com
Status: Confirmed

CVE: CVE-2026-83509 (🔒)
GCVE (CVE): GCVE-0-2026-83509
GCVE (VulDB): GCVE-100-418845
scip Labs: https://www.scip.ch/en/?labs.20161215

Entryinfo

Created: 10/14/2026 02:36
Changes: 10/14/2026 02:36 (63)
Complete: 🔍
Cache ID: 216::103

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Discussion

No comments yet. Languages: en.

Please log in to comment.

◂ PreviousOverviewNext ▸

Do you want to use VulDB in your project?

Use the official API to access entries easily!