How severe is CVE-2020-3959?

CVE-2020-3959 has a CVSS 3.x base score of 3.3, rated low severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability low.

Is CVE-2020-3959 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (22nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-3959?

CVE-2020-3959 primarily affects Vmware Fusion. In total, 186 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2020-3959?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2020-3959 published?

CVE-2020-3959 was published on 2020-05-29 and last updated on 2026-06-17.

CVE-2020-3959

CVE-2020-3959 is a low-severity vulnerability in Vmware Fusion with a CVSS 3.x base score of 3.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-401.

Key facts

Severity: Low (CVSS 3.x base score 3.3)
CVSS v2: 2.1
EPSS exploit prediction: 0% (22nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-401
Affected product: Vmware Fusion
Published: 2020-05-29
Last modified: 2026-06-17

Description

VMware ESXi (6.7 before ESXi670-202004101-SG and 6.5 before ESXi650-202005401-SG), VMware Workstation (15.x before 15.1.0) and VMware Fusion (11.x before 11.1.0) contain a memory leak vulnerability in the VMCI module. A malicious actor with local non-administrative access to a virtual machine may be able to crash the virtual machine's vmx process leading to a partial denial of service.

Frequently asked questions

What is CVE-2020-3959?: VMware ESXi (6.7 before ESXi670-202004101-SG and 6.5 before ESXi650-202005401-SG), VMware Workstation (15.x before 15.1.0) and VMware Fusion (11.x before 11.1.0) contain a memory leak vulnerability in the VMCI module. A malicious actor with local non-administrative access to a virtual machine may be able to crash the virtual machine's vmx process leading to a partial denial of service.
How severe is CVE-2020-3959?: CVE-2020-3959 has a CVSS 3.x base score of 3.3, rated low severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability low.
Is CVE-2020-3959 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (22nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-3959?: CVE-2020-3959 primarily affects Vmware Fusion. In total, 186 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-3959?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2020-3959 published?: CVE-2020-3959 was published on 2020-05-29 and last updated on 2026-06-17.

References

https://www.vmware.com/security/advisories/VMSA-2020-0011.html

Affected products (186)

cpe:2.3:a:vmware:fusion:*:*:*:*:*:*:*:*
cpe:2.3:a:vmware:workstation:*:*:*:*:*:*:*:*
cpe:2.3:o:vmware:esxi:6.5:-:*:*:*:*:*:*
cpe:2.3:o:vmware:esxi:6.5:650-201701001:*:*:*:*:*:*
cpe:2.3:o:vmware:esxi:6.5:650-201703001:*:*:*:*:*:*
cpe:2.3:o:vmware:esxi:6.5:650-201703002:*:*:*:*:*:*
cpe:2.3:o:vmware:esxi:6.5:650-201704001:*:*:*:*:*:*
cpe:2.3:o:vmware:esxi:6.5:650-201707101:*:*:*:*:*:*
cpe:2.3:o:vmware:esxi:6.5:650-201707102:*:*:*:*:*:*
cpe:2.3:o:vmware:esxi:6.5:650-201707103:*:*:*:*:*:*
cpe:2.3:o:vmware:esxi:6.5:650-201707201:*:*:*:*:*:*
cpe:2.3:o:vmware:esxi:6.5:650-201707202:*:*:*:*:*:*
cpe:2.3:o:vmware:esxi:6.5:650-201707203:*:*:*:*:*:*
cpe:2.3:o:vmware:esxi:6.5:650-201707204:*:*:*:*:*:*
cpe:2.3:o:vmware:esxi:6.5:650-201707205:*:*:*:*:*:*
cpe:2.3:o:vmware:esxi:6.5:650-201707206:*:*:*:*:*:*
cpe:2.3:o:vmware:esxi:6.5:650-201707207:*:*:*:*:*:*
cpe:2.3:o:vmware:esxi:6.5:650-201707208:*:*:*:*:*:*
cpe:2.3:o:vmware:esxi:6.5:650-201707209:*:*:*:*:*:*
cpe:2.3:o:vmware:esxi:6.5:650-201707210:*:*:*:*:*:*
cpe:2.3:o:vmware:esxi:6.5:650-201707211:*:*:*:*:*:*
cpe:2.3:o:vmware:esxi:6.5:650-201707212:*:*:*:*:*:*
cpe:2.3:o:vmware:esxi:6.5:650-201707213:*:*:*:*:*:*
cpe:2.3:o:vmware:esxi:6.5:650-201707214:*:*:*:*:*:*
cpe:2.3:o:vmware:esxi:6.5:650-201707215:*:*:*:*:*:*
cpe:2.3:o:vmware:esxi:6.5:650-201707216:*:*:*:*:*:*
cpe:2.3:o:vmware:esxi:6.5:650-201707217:*:*:*:*:*:*
cpe:2.3:o:vmware:esxi:6.5:650-201707218:*:*:*:*:*:*
cpe:2.3:o:vmware:esxi:6.5:650-201707219:*:*:*:*:*:*
cpe:2.3:o:vmware:esxi:6.5:650-201707220:*:*:*:*:*:*
cpe:2.3:o:vmware:esxi:6.5:650-201707221:*:*:*:*:*:*
cpe:2.3:o:vmware:esxi:6.5:650-201710001:*:*:*:*:*:*
cpe:2.3:o:vmware:esxi:6.5:650-201712001:*:*:*:*:*:*
cpe:2.3:o:vmware:esxi:6.5:650-201803001:*:*:*:*:*:*
cpe:2.3:o:vmware:esxi:6.5:650-201806001:*:*:*:*:*:*
cpe:2.3:o:vmware:esxi:6.5:650-201808001:*:*:*:*:*:*
cpe:2.3:o:vmware:esxi:6.5:650-201810001:*:*:*:*:*:*
cpe:2.3:o:vmware:esxi:6.5:650-201810002:*:*:*:*:*:*
cpe:2.3:o:vmware:esxi:6.5:650-201811001:*:*:*:*:*:*
cpe:2.3:o:vmware:esxi:6.5:650-201811002:*:*:*:*:*:*

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