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Uncontrolled Resource ConsumptionWeakness · CWE-400

CVE-2025-41226

MEDIUM · 6.8 CVSS v3.1 Published 2025-05-20
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
70/100
Remediation priority · Elevated
Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
VMware ESXi contains a denial-of-service vulnerability that occurs when performing a guest operation. A malicious actor with guest operation privileges on a VM, who is already authenticated through vCenter Server or ESXi may trigger this issue to create a denial-of-service condition of guest VMs with VMware Tools running and guest operations enabled.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

VMware ESXi contains a denial-of-service vulnerability in the guest operations subsystem. An authenticated attacker with guest operation privileges on a virtual machine can trigger the vulnerability to cause a DoS condition on guest VMs that have VMware Tools installed and guest operations enabled.

MitigationDisable guest operations on VMs where not required, or apply VMware's official patch when available. Restrict guest operation privileges to only necessary users and monitor for abuse.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Adjacent
Complexity
Low
Privileges
Low
User interaction
None
Scope
Changed
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify the ESXi version
    Run 'vmware -l' or check the VMware vSphere Client for the ESXi version under Host > Configuration > General > Version
    Affected if The installed version falls within the vulnerable range (compare to VMware's official advisory for CVE-2025-41226)
  2. List virtual machines with guest operations enabled
    Using PowerCLI: Get-VM | Get-AdvancedSetting -Name 'guestOperationsEnabled' or check via vSphere Client under VM > Settings > Options > Guest OS > Guest Operations
    Affected if Any VM has guest operations enabled (value is true) and has VMware Tools installed
  3. Verify VMware Tools installation status
    Run 'Get-VM | Select-Object Name, @{N='ToolsStatus';E={$_.Guest.ToolsStatus}}' in PowerCLI, or check in vSphere Client under VM > Summary > VMware Tools
    Affected if The target VM has VMware Tools installed (status shows 'Running' or 'OK') - this is a prerequisite for the vulnerability
  4. Audit guest operation privileges
    Check RBAC permissions in vSphere: Go to Permissions in the vSphere Web Client and review who has 'Guest Operations' privileges assigned, or run Get-VIPermission | Where-Object {$_.Role -match 'Guest'} in PowerCLI
    Affected if Users or groups are assigned guest operation privileges on any VM (these users could trigger the DoS)

Your environment is affected if you run a vulnerable ESXi version AND have any VMs with both guest operations enabled and VMware Tools installed, where untrusted users possess guest operation privileges.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Disable guest operations on VMs where not required, or apply VMware's official patch when available. Restrict guest operation privileges to only necessary users and monitor for abuse.

Recommended fix Moderate confidence

Apply the VMware ESXi patch for CVE-2025-41226 (consult support.broadcom.com for the exact fixed ESXi version)

  1. Check the VMware ESXi version currently installed by running 'vmware -l' or reviewing the host client
  2. Identify the specific patch or update needed by searching VMware ESXi release notes on support.broadcom.com for CVE-2025-41226
  3. Download the corresponding VMware ESXi patch from Broadcom Support Portal (support.broadcom.com)
  4. Upload the patch to the ESXi host via SSH or ESXi Host Client
  5. Enable maintenance mode on the ESXi host: 'esxcli system maintenanceMode set --enable true'
  6. Apply the patch using 'esxcli software vib update -d /path/to/patch.zip'
  7. Reboot the ESXi host after patch application
  8. Verify patch installation: 'esxcli software vib list | grep -i vmware'
Caveat Patching ESXi may require brief downtime; test in staging before production deployment; ensure backup of VM data exists

Generated from the published advisory — verify against the referenced sources before acting.

Have this fixed Scoped from the published advisory
  • Consultation3.0 h
  • Implementation4.0 h
  • Testing4.0 h
  • Review / QA2.0 h
13.0 hours of engineering $2,280
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2025-41226 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data