Microsoft Windows 26H1 Container Isolation FS Filter Driver unionfs.sys out-of-bounds

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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2.2$0-$5k0.00

Summaryinfo

A vulnerability identified as problematic has been detected in Microsoft Windows 26H1. Affected is an unknown function of the file unionfs.sys of the component Container Isolation FS Filter Driver. This manipulation causes out-of-bounds. This vulnerability is handled as CVE-2026-50428. It is possible to launch the attack on the local host. There is not any exploit available.

Detailsinfo

A vulnerability has been found in Microsoft Windows 26H1 and classified as problematic. Affected by this vulnerability is some unknown functionality of the file unionfs.sys of the component Container Isolation FS Filter Driver. The manipulation with an unknown input leads to a out-of-bounds vulnerability. The CWE definition for the vulnerability is CWE-125. The product reads data past the end, or before the beginning, of the intended buffer. As an impact it is known to affect confidentiality. The summary by CVE is:

Out-of-bounds read in Windows Container Isolation FS Filter Driver (unionfs.sys) allows an authorized attacker to disclose information locally.

It is possible to read the advisory at msrc.microsoft.com. This vulnerability is known as CVE-2026-50428 since 06/04/2026. The exploitation appears to be easy. Attacking locally is a requirement. The exploitation needs additional levels of successful authentication. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 07/14/2026).

Upgrading to version 10.0.28000.2269 eliminates this vulnerability.

Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

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Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 2.3
VulDB Meta Temp Score: 2.2

VulDB Base Score: 2.3
VulDB Temp Score: 2.2
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

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

Exploitinginfo

Class: Out-of-bounds
CWE: CWE-125 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: No

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

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Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔒

Upgrade: Windows 10.0.28000.2269

Timelineinfo

06/04/2026 CVE reserved
07/14/2026 +40 days Advisory disclosed
07/14/2026 +0 days VulDB entry created
07/14/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: microsoft.com
Product: microsoft.com

Advisory: msrc.microsoft.com
Status: Confirmed

CVE: CVE-2026-50428 (🔒)
GCVE (CVE): GCVE-0-2026-50428
GCVE (VulDB): GCVE-100-378751

Entryinfo

Created: 07/14/2026 23:26
Changes: 07/14/2026 23:26 (55)
Complete: 🔍
Cache ID: 216::103

Be aware that VulDB is the high quality source for vulnerability data.

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