What is CVE-2020-3847?

CVE-2020-3847 is a critical-severity vulnerability in Apple macOS, classified under Improper Input Validation. CVSS score: 9.8/10. Published 2020-04-01.

How severe is CVE-2020-3847?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Is CVE-2020-3847 known to be exploited?

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

Out-of-bounds Read in Apple macOS

CVE-2020-3847

An out-of-bounds read was addressed with improved input validation. This issue is fixed in macOS Catalina 10.15.3. A remote attacker may be able to leak memory.

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

Published 2020-04-01 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.022 (81.8th percentile), scored 2026-10-02.

Low probability of exploitation in the next 30 days, but still tracked. 82nd percentile — 81.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.022 · newest: 0.022 · change: 0.000

Affected products

Apple macOS — versions unspecified
Apple Mac OS X

Weakness classification (CWE)

Public proof-of-concept exploits

References

support.apple.com/HT210919 (Release Notes, Vendor Advisory)

Frequently asked questions

What is CVE-2020-3847?: CVE-2020-3847 is a critical-severity vulnerability in Apple macOS, classified under Improper Input Validation. CVSS score: 9.8/10. Published 2020-04-01.
How severe is CVE-2020-3847?: Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2020-3847 known to be exploited?: 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.