CVE-2026-69807 in Windows
Summary
by MITRE • 09/09/2026
Improper limitation of a pathname to a restricted directory ('path traversal') in Windows PowerShell allows an authorized attacker to elevate privileges over a network.
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Analysis
by VulDB Data Team • 09/09/2026
The vulnerability described constitutes a critical path traversal flaw within Microsoft Windows PowerShell, specifically categorized under CWE-22: Improper Limitation of a Pathname to a Restricted Directory. This security defect arises from insufficient validation or sanitization of user-supplied input when constructing file paths for internal operations. In the context of PowerShell, this typically manifests when scripts or cmdlets process relative paths or environment variables without adequately resolving them against the intended secure base directory. An attacker who has already gained authorized access to a system can exploit this logic error by manipulating path arguments to reference files located outside the restricted scope. This manipulation allows the execution engine to read sensitive configuration files, inject malicious content into trusted scripts, or overwrite critical system binaries that reside in higher-privilege directories such as System32 or Program Files.
From an operational perspective, the impact of this vulnerability is severe due to its potential for privilege escalation over a network. While PowerShell itself runs with the permissions of the invoking user, many administrative tasks and scheduled jobs are executed under elevated contexts, including SYSTEM account privileges. By leveraging path traversal, an attacker can redirect execution flow or data input toward files that are processed by these high-privilege processes. For instance, if a privileged script inadvertently sources a file from a writable directory due to the path resolution flaw, it may execute arbitrary code with administrative rights. This capability effectively bypasses standard access control mechanisms, allowing a low-privileged user to achieve full system compromise remotely without requiring additional exploitation vectors like buffer overflows or kernel exploits.
This vulnerability aligns closely with MITRE ATT&CK technique T1059: Command and Scripting Interpreter, specifically the PowerShell sub-category. The attack vector often involves techniques such as T1204: User Execution, where an attacker tricks a user into running a malicious script that contains the crafted path traversal payload. Furthermore, it relates to T1068: Exploitation for Privilege Escalation, as the core objective is to move from a standard user context to an administrative or system-level identity. The exploitation relies on the principle of least privilege being violated through improper input handling rather than a failure in authentication or encryption protocols.
Mitigation strategies must focus on both immediate remediation and long-term architectural hardening. Microsoft has addressed this issue through specific security updates that enforce stricter path validation within PowerShell cmdlets, ensuring that relative paths are resolved securely against the expected directory structure before any file operations occur. Administrators should ensure all Windows systems are updated with the latest cumulative patches to close these logic gaps. Additionally, implementing strict script execution policies can limit the ability of unauthorized scripts to run arbitrary code. Enforcing Code Integrity and using Application Control solutions like AppLocker or Windows Defender Application Control helps prevent untrusted binaries from executing in privileged directories. Regular auditing of PowerShell logs for unusual path resolutions and restricting write permissions on critical system folders further reduces the attack surface available to potential adversaries exploiting this flaw.