Actively exploited

CVE-2025-22224 VMware ESXi and Workstation TOCTOU Race Condition Vulnerability

VMware ESXi and Workstation contain a time-of-check time-of-use (TOCTOU) race condition vulnerability that leads to an out-of-bounds write. Successful exploitation enables an attacker with local administrative privileges on a virtual machine to execute code as the virtual machine's VMX process running on the host.

From the CISA KEV catalogue version 2026.11.06, with Cybergen analysis. Updated 6 Nov 2026.

Our Assessment

Should You Worry?

Patch nowCybergen assessment
  • CISA confirmed exploitation in the wild and added it to the Known Exploited Vulnerabilities catalogue on 4 Mar 2025.
  • Rated Critical severity (CVSS 9.3, scored by Vendor).
  • This product type is often exposed to the internet, which is where attackers scan for it first.
  • It has been in the catalogue for 612 days. Systems still unpatched now have almost certainly been scanned for it.
The Vulnerability

What It Is

VMware ESXi, and Workstation contain a TOCTOU (Time-of-Check Time-of-Use) vulnerability that leads to an out-of-bounds write. A malicious actor with local administrative privileges on a virtual machine may exploit this issue to execute code as the virtual machine's VMX process running on the host.

Affected Versions

ProductVersions
VMware ESXi8.0 to before ESXi80U3d-24585383
8.0 to before ESXi80U2d-24585300
7.0 to before ESXi70U3s-24585291
VMware Workstation17.x to before 17.6.3
VMware VMware Cloud Foundation5.x, 4.5.x
VMware Telco Cloud Platform5.x, 4.x, 3.x, 2.x
VMware Telco Cloud Infrastructure3.x, 2.x

From the public CVE record, as supplied by the vendor. Always confirm against the vendor advisory.

From Watch to Action

What To Do Now

  1. 1

    Find it

    Search your asset inventory and external attack surface for VMware ESXi and Workstation. Include cloud images, appliances and anything a supplier runs for you.

    Attack Surface Management
  2. 2

    Fix it

    Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

    Vulnerability Management
  3. 3

    Hunt for compromise

    If an affected system was reachable before you patched, assume it may have been hit. Check logs, new accounts, web shells and outbound connections from the date of exposure.

    Incident Response
  4. 4

    Prove it is fixed

    Rescan or test the system after patching. Upgrades that fail silently and forgotten secondary instances are common.

    Penetration Testing

Not Sure If You Are Exposed?

Our attack surface and vulnerability teams can check your internet-facing estate for CVE-2025-22224 and every other exploited flaw on the list.

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