VDB-340769 · CVE-2026-20834 · GCVE-0-2026-20834

Microsoft Windows up to Server 2025 absolute path traversal

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.
3.6	$0-$5k	0.00

Summaryinfo

A vulnerability identified as problematic has been detected in Microsoft Windows. Affected by this vulnerability is an unknown functionality. The manipulation leads to absolute path traversal. This vulnerability is traded as CVE-2026-20834. It is possible to launch the attack on the physical device. There is no exploit available. It is suggested to install a patch to address this issue.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in Microsoft Windows. This issue affects some unknown functionality. The manipulation with an unknown input leads to a absolute path traversal vulnerability. Using CWE to declare the problem leads to CWE-36. The product uses external input to construct a pathname that should be within a restricted directory, but it does not properly neutralize absolute path sequences such as "/abs/path" that can resolve to a location that is outside of that directory. Impacted is confidentiality. The summary by CVE is:

Absolute path traversal in Windows Shell allows an unauthorized attacker to perform spoofing with a physical attack.

The weakness was shared 01/13/2026 as confirmed security update guide (Website). The advisory is shared at msrc.microsoft.com. The identification of this vulnerability is CVE-2026-20834. The exploitation is known to be easy. An attack has to be approached locally. No form of authentication is needed for a successful exploitation. Neither technical details nor an exploit are publicly available. MITRE ATT&CK project uses the attack technique T1006 for this issue.

Applying a patch is able to eliminate this problem. A possible mitigation has been published immediately after the disclosure of the vulnerability.

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Type

Operating System

Vendor

Microsoft

Name

Windows

Version

License

commercial

Website

Vendor: https://www.microsoft.com/
Product: https://www.microsoft.com/en-us/windows

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 3.9
VulDB Meta Temp Score: 3.6

VulDB Base Score: 2.4
VulDB Temp Score: 2.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

Vendor Base Score (Microsoft): 4.6
Vendor Vector (Microsoft): 🔒

CNA Base Score: 4.6
CNA Vector (Microsoft): 🔒

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

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

Exploitinginfo

Class: Absolute path traversal
CWE: CWE-36 / CWE-22
CAPEC: 🔒
ATT&CK: 🔒

Physical: Yes
Local: Yes
Remote: No

Availability: 🔒
Status: Unproven

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Patch
Status: 🔍

Reaction Time: 🔒
0-Day Time: 🔒
Exposure Time: 🔒

Timelineinfo

01/13/2026 VulDB entry created
01/13/2026 +0 days Advisory disclosed
01/13/2026 +0 days Countermeasure disclosed
01/16/2026 +3 days VulDB entry last update

Sourcesinfo

Vendor: microsoft.com
Product: microsoft.com

Advisory: msrc.microsoft.com
Status: Confirmed

CVE: CVE-2026-20834 (🔒)
GCVE (CVE): GCVE-0-2026-20834
GCVE (VulDB): GCVE-100-340769
scip Labs: https://www.scip.ch/en/?labs.20161215

Entryinfo

Created: 01/13/2026 19:24
Updated: 01/16/2026 11:33
Changes: 01/13/2026 19:24 (35), 01/13/2026 19:27 (33), 01/16/2026 11:33 (12)
Complete: 🔍
Cache ID: 216::103