CVE-2026-40058 in Falcon Sensor
Summary
by MITRE • 09/15/2026
CrowdStrike released a security update to address a vulnerability in the Falcon sensor for Windows. The vulnerability only exists when the Microsoft Office File Malicious Macro Removal Windows policy setting is enabled and customers remain protected through the Cloud Anti-malware for Microsoft Office Files settings.
An update is available immediately for versions 7.34 and above, 7.32 LTS, and 7.16 for Windows 7/2008 R2 systems. The Falcon sensor for Mac, Linux, and Legacy Systems are not affected.
This vulnerability could expose an arbitrary file write to protected locations from an unprivileged context, potentially leading to local privilege escalation.
The CrowdStrike Laroux Malware Cleanup Tool, based off of the same feature in the CrowdStrike Falcon sensor for Windows, is also affected. An update for this tool is also available immediately.
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Analysis
by VulDB Data Team • 09/15/2026
A recently disclosed vulnerability within the CrowdStrike Falcon sensor for Windows presents a significant security risk related to improper access control and potential local privilege escalation. This flaw specifically manifests when specific Microsoft Office protection policies are active on the endpoint, namely the File Malicious Macro Removal policy setting being enabled in conjunction with Cloud Anti-malware for Microsoft Office Files settings. The vulnerability allows an attacker operating from an unprivileged context to exploit a logic error that results in an arbitrary file write operation targeting protected system locations. This capability bypasses standard user-level restrictions, enabling the modification of critical files or configurations without requiring elevated privileges initially.
The technical nature of this flaw aligns with CWE-732, which describes improper permission assignment for critical resources, and can be mapped to MITRE ATT&CK technique T1055, specifically Process Injection or File Write operations used by adversaries to establish persistence or escalate privileges on compromised systems. By leveraging the interaction between the Falcon sensor's macro removal features and Windows file system permissions, an attacker could potentially overwrite sensitive binaries, configuration files, or registry entries located in protected directories such as Program Files or System32. This arbitrary write capability serves as a critical stepping stone for local privilege escalation, allowing low-privilege users to gain administrative control over the affected host by manipulating security-critical components that are typically restricted from user-level modification.
The operational impact of this vulnerability is severe due to its potential to compromise the integrity and confidentiality of the entire endpoint environment. If successfully exploited, an adversary could install malicious software, disable security controls, or exfiltrate sensitive data with elevated privileges. It is important to note that this vulnerability is specific to certain configurations involving Microsoft Office macro handling and does not affect all deployments universally. Furthermore, the CrowdStrike Falcon sensor for Mac, Linux, and Legacy Systems remains unaffected by this particular flaw. However, the CrowdStrike Laroux Malware Cleanup Tool, which shares underlying code with the Windows Falcon sensor feature involved in this vulnerability, is also susceptible to similar exploitation vectors requiring immediate attention.
To mitigate these risks, organizations must apply the available security updates immediately for affected versions of the Falcon sensor and the Laroux tool. Updates are provided for version 7.34 and above, as well as specific long-term support (LTS) releases like 7.32 and legacy systems running Windows 7 or Server 2008 R2 under version 7.16. Administrators should verify their current sensor versions against these release criteria and deploy the patches across all affected endpoints to close the privilege escalation gap. Additionally, reviewing Microsoft Office macro settings may provide an additional layer of defense by disabling specific policies if they are not strictly required for business operations, thereby reducing the attack surface associated with this vulnerability until full patching is confirmed across the infrastructure.