What is CVE-2020-27945?

CVE-2020-27945 is a high-severity vulnerability in Apple macOS, classified under Integer Overflow or Wraparound. CVSS score: 7.8/10. Published 2021-04-02.

How severe is CVE-2020-27945?

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

Integer overflow in Apple macOS

CVE-2020-27945

An integer overflow was addressed with improved input validation. This issue is fixed in macOS Big Sur 11.2, Security Update 2021-001 Catalina, Security Update 2021-001 Mojave, macOS Big Sur 11.0.1. Processing maliciously crafted web content may lead to arbitrary code execution.

Vulnerability class: Integer Overflow

Published 2021-04-02 · 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: 0.007 (52.3th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 52nd percentile — 52.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.007 · newest: 0.007 · change: 0.000

Affected products

Apple macOS — versions unspecified
Apple Mac OS X — versions 10.14.6, 10.15.7

Weakness classification (CWE)

CWE-190 — Integer Overflow or Wraparound

References

support.apple.com/en-us/HT211931 (Vendor Advisory)
support.apple.com/en-us/HT212147 (Vendor Advisory)

Frequently asked questions

What is CVE-2020-27945?: CVE-2020-27945 is a high-severity vulnerability in Apple macOS, classified under Integer Overflow or Wraparound. CVSS score: 7.8/10. Published 2021-04-02.
How severe is CVE-2020-27945?: High severity. CVSS v3 base score is 7.8 out of 10.