What is CVE-2020-9853?

CVE-2020-9853 is a high-severity vulnerability in Apple macOS, classified under Improper Input Validation. CVSS score: 7.8/10. Published 2020-10-22.

How severe is CVE-2020-9853?

High severity. CVSS v3 base score is 7.8 out of 10.

Is CVE-2020-9853 known to be exploited?

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

Buffer overflow in Apple macOS

CVE-2020-9853

A memory corruption issue was addressed with improved validation. This issue is fixed in macOS Catalina 10.15.4. A malicious application may be able to determine kernel memory layout.

Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)

Published 2020-10-22 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.008 (54.7th percentile), scored 2026-10-02.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 55th percentile — 54.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.008 · newest: 0.008 · change: 0.000

Affected products

Apple macOS — versions unspecified
Apple Mac OS X

Weakness classification (CWE)

Public proof-of-concept exploits

didi/kemon

References

support.apple.com/kb/HT211100 (Vendor Advisory)

Frequently asked questions

What is CVE-2020-9853?: CVE-2020-9853 is a high-severity vulnerability in Apple macOS, classified under Improper Input Validation. CVSS score: 7.8/10. Published 2020-10-22.
How severe is CVE-2020-9853?: High severity. CVSS v3 base score is 7.8 out of 10.
Is CVE-2020-9853 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.