Memory Leak Vulnerability in VMware HGFS (CVE-2025-22226)

Historical catalog analysis: CISA added this entry on March 04, 2025. The entry reflects catalog information retrieved on August 31, 2026, not a snapshot archived on the inclusion date. Check current vendor guidance before acting.

What the vulnerability is

CVE-2025-22226 is an information disclosure vulnerability characterized by an out-of-bounds read (CWE-125) within the Host Guest File System (HGFS). This flaw allows a user who has already obtained administrative privileges on a guest virtual machine to leak memory from the vmx process on the host.

Exposure and applicability

This vulnerability affects VMware ESXi, Workstation, and Fusion. The primary exposure path requires the attacker to have administrative-level access to a virtual machine (VM) running on the affected hypervisor or workstation software. Because this is a guest-to-host information leak, the risk is highest in environments where VM administrative privileges are granted to untrusted users or where existing compromises of guest VMs could lead to further host-level data exposure.

Remediation priorities

Based on the inclusion of this vulnerability in CISA’s Known Exploited Vulnerabilities (KEV) catalog as of March 4, 2025, remediation should be prioritized for systems where administrative access to guest VMs is decentralized or managed by third parties.

Our analysis suggests the following priority sequence:
1. Identify Affected Assets: Inventory all instances of VMware ESXi, Workstation, and Fusion across the infrastructure.
2. Apply Vendor Mitigations: Deploy updates or configuration changes as specified in the vendor’s security advisory to address the HGFS out-of-bounds read.
3. Cloud Service Review: For organizations utilizing cloud services, review alignment with BOD 22-01 guidance regarding the remediation of known exploited vulnerabilities.
4. Decommissioning: If mitigations are unavailable for specific legacy versions in use, consider discontinuing the use of those products to eliminate the exposure path.

How to validate remediation

Verification must move beyond simple version checks. While updating to a patched version is the primary corrective action, defenders should verify that the mitigation has actually reduced exposure by:
* Confirming Patch Application: Validating through configuration management tools that the specific vendor-provided fix for CVE-2025-22226 is active across all hosts.
* Reviewing HGFS Configuration: If a workaround involving the disabling of HGFS was used, verifying that the feature is inactive on high-risk VMs.

It is important to note that a version string update does not inherently prove that the memory leak is mitigated; validation should be tied to the successful deployment of the vendor’s specific remediation instructions.

Limits and open questions

There are several unknowns regarding this vulnerability. The source indicates that known use by ransomware campaigns is currently unknown. Additionally, while the entry path (administrative privileges on a VM) is defined, the specific types of sensitive data residing in the vmx process memory that could be leaked remain unspecified. Residual risk persists if administrative access to guest VMs cannot be strictly controlled, as this remains the prerequisite for exploitation.

Source and editorial note

CVE-2025-22226: VMware ESXi, Workstation, and Fusion Information Disclosure Vulnerability · Source date: March 04, 2025 · Retrieved August 31, 2026.

Material facts are tied to the cited primary source. Recommendations are independent defensive analysis unless attributed to the source. Confirm consequential decisions against current authoritative guidance.

Archive date: March 07, 2025. The displayed post date is assigned three days after the source date to organize this retrospective archive; it does not mean this site published the analysis then. First published by this site: October 23, 2026 at 00:05 UTC.

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