CVE-2020-3959

Guest VM interruption via VMCI memory leak

Published May 29, 2020 · Updated Aug 4, 2024

Memory leak in the VMCI module in VMware ESXi, Workstation, and Fusion allows local users to crash a virtual machine's VMX process. The VMCI module fails to release memory during an undisclosed guest operation; VMware has not identified the affected function or input. The attacker requires non-administrative access inside a guest, and exploitation interrupts only that virtual machine by terminating its VMX process.

CVSS severity3.3
Low
EPSS probability0.31%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Memory leak in the VMCI module in VMware ESXi, Workstation, and Fusion allows local users to crash a virtual machine's VMX process. The VMCI module fails to release memory during an undisclosed guest operation; VMware has not identified the affected function or input. The attacker requires non-administrative access inside a guest, and exploitation interrupts only that virtual machine by terminating its VMX process.

The record

CVE
CVE-2020-3959
Published
May 29, 2020
Updated
Aug 4, 2024
Vendor
VMware
Product
VMware Workstation
Classifications
CWE-401, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 29, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=15.x before 15.1.0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

VMware · VMware Workstationversion=15.x before 15.1.0
VMware · VMware Fusionversion=11.x before 11.1.0
VMware · VMware ESXiversion=6.5 before ESXi650-202005401-SG; version=6.7 before ESXi670-202004101-SG

Published CVSS scores

3.3NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
3.3VMwareCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-401Missing Release of Memory after Effective Lifetime
T1499.004Endpoint Denial of Service: Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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