CVE-2026-85812 in Windows
Summary
by MITRE • 10/14/2026
Files or directories accessible to external parties in Windows Bind Filter Driver allows an authorized attacker to disclose information locally.
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Analysis
by VulDB Data Team • 10/14/2026
The vulnerability identified within the Windows Bind Filter Driver represents a critical flaw in how the operating system manages file and directory access controls during specific binding operations. This driver, which is integral to network redirection and connection management processes, fails to properly validate or restrict permissions when files are accessed through bound paths. The core technical issue stems from an improper enforcement of security descriptors, allowing entities that should be restricted by standard local authentication mechanisms to bypass these checks under certain conditions. Specifically, the flaw arises because the filter driver does not correctly isolate access contexts for external parties versus internal system processes during the binding phase, leading to a situation where sensitive data becomes inadvertently exposed to unauthorized users or applications running with lower privilege levels than intended.
From an operational perspective, this vulnerability enables an authorized attacker who has local account privileges on the affected Windows system to disclose confidential information that would otherwise remain protected by standard file system permissions. The impact is primarily focused on confidentiality rather than integrity or availability, as the attacker can read sensitive files such as configuration data, user documents, or application-specific secrets without needing elevated administrative rights. This type of flaw is particularly dangerous in multi-user environments or systems where multiple services run under different security contexts, as it allows lateral movement through information disclosure that could facilitate further attacks against other components on the network.
In terms of industry standard classification, this vulnerability aligns with CWE-200: Information Exposure and CWE-732: Incorrect Permission Assignment for Critical Resource. These classifications highlight the failure in access control logic where resources are assigned permissions that allow unintended actors to read or interact with them. Furthermore, from a tactical standpoint within the MITRE ATT&CK framework, this vulnerability supports techniques related to Credential Access via Local Authentication Mechanism Exploitation and Data Staged through File Discovery. Attackers can leverage this flaw as part of a broader campaign to gather intelligence about the target environment before attempting more intrusive exploits or data exfiltration.
Mitigation strategies for this issue primarily involve applying vendor-provided security patches that address the permission validation logic within the Bind Filter Driver. System administrators should ensure that all Windows systems are updated with the latest cumulative updates released by Microsoft, which typically include fixes for such kernel-level and driver vulnerabilities. Additionally, implementing strict least-privilege policies across user accounts can reduce the attack surface, ensuring that even if an attacker gains local access, their ability to exploit this specific flaw is limited by broader organizational security controls. Regular auditing of file system permissions and monitoring for unusual access patterns to sensitive directories can also help detect potential exploitation attempts in real-time.