What is CVE-2019-8656?

CVE-2019-8656 is a medium-severity vulnerability in Apple macOS. CVSS score: 5.5/10. Published 2020-10-27.

How severe is CVE-2019-8656?

Medium severity. CVSS v3 base score is 5.5 out of 10.

Is CVE-2019-8656 known to be exploited?

6 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Vulnerability in Apple macOS

CVE-2019-8656

This was addressed with additional checks by Gatekeeper on files mounted through a network share. This issue is fixed in macOS Mojave 10.14.6, Security Update 2019-004 High Sierra, Security Update 2019-004 Sierra. Extracting a zip file containing a symbolic link to an endpoint in an NFS mount that is attacker controlled may bypass Gatekeeper.

Published 2020-10-27 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N.

EPSS exploit prediction

EPSS: 0.015 (73.2th percentile), scored 2026-10-02.

Low probability of exploitation in the next 30 days, but still tracked. 73rd percentile — 73.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.015 · newest: 0.015 · change: 0.000

Affected products

Apple macOS — versions unspecified
Apple Mac OS X

Public proof-of-concept exploits

References

support.apple.com/en-us/HT210348 (Vendor Advisory)

Frequently asked questions

What is CVE-2019-8656?: CVE-2019-8656 is a medium-severity vulnerability in Apple macOS. CVSS score: 5.5/10. Published 2020-10-27.
How severe is CVE-2019-8656?: Medium severity. CVSS v3 base score is 5.5 out of 10.
Is CVE-2019-8656 known to be exploited?: 6 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.