What is CVE-2020-9856?

CVE-2020-9856 is a medium-severity vulnerability in Apple macOS. CVSS score: 5.3/10. Published 2020-06-09.

How severe is CVE-2020-9856?

Medium severity. CVSS v3 base score is 5.3 out of 10.

Is CVE-2020-9856 known to be exploited?

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

Vulnerability in Apple macOS

CVE-2020-9856

This issue was addressed with improved checks. This issue is fixed in macOS Catalina 10.15.5. An application may be able to gain elevated privileges.

Published 2020-06-09 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L.

EPSS exploit prediction

EPSS: 0.014 (71.3th percentile), scored 2026-10-02.

Low probability of exploitation in the next 30 days, but still tracked. 71st percentile — 71.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.014 · newest: 0.014 · change: 0.000

Affected products

Apple macOS — versions unspecified
Apple Mac OS X — versions 10.13.6, 10.14.6

Public proof-of-concept exploits

References

support.apple.com/HT211170 (Vendor Advisory)

Frequently asked questions

What is CVE-2020-9856?: CVE-2020-9856 is a medium-severity vulnerability in Apple macOS. CVSS score: 5.3/10. Published 2020-06-09.
How severe is CVE-2020-9856?: Medium severity. CVSS v3 base score is 5.3 out of 10.
Is CVE-2020-9856 known to be exploited?: 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.