What is CVE-2020-9851?

CVE-2020-9851 is a medium-severity vulnerability in Apple macOS. CVSS score: 5.5/10. Published 2020-06-09.

How severe is CVE-2020-9851?

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

Vulnerability in Apple macOS

CVE-2020-9851

An access issue was addressed with improved access restrictions. This issue is fixed in macOS Catalina 10.15.5. A malicious application may be able to modify protected parts of the file system.

Published 2020-06-09 · 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: 0.006 (47.0th percentile), scored 2026-10-02.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 47th percentile — 47.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: 0.000

Affected products

Apple macOS — versions unspecified
Apple Mac OS X

References

support.apple.com/HT211170 (Vendor Advisory)

Frequently asked questions

What is CVE-2020-9851?: CVE-2020-9851 is a medium-severity vulnerability in Apple macOS. CVSS score: 5.5/10. Published 2020-06-09.
How severe is CVE-2020-9851?: Medium severity. CVSS v3 base score is 5.5 out of 10.