What is CVE-2020-9940?

CVE-2020-9940 is a high-severity vulnerability in Apple iOS, classified under Buffer Copy without Checking Size of Input (Classic Buffer Overflow). CVSS score: 7.8/10. Published 2020-10-22.

How severe is CVE-2020-9940?

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

Buffer overflow in Apple iOS

CVE-2020-9940

A buffer overflow issue was addressed with improved memory handling. This issue is fixed in iOS 13.6 and iPadOS 13.6, macOS Catalina 10.15.6, tvOS 13.4.8. Processing a maliciously crafted USD file may lead to unexpected application termination or arbitrary code execution.

Vulnerability class: Buffer Overflow

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: 0.013 (70.4th percentile), scored 2026-10-01.

Low probability of exploitation in the next 30 days, but still tracked. 70th percentile — 70.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.013 · newest: 0.013 · change: 0.000

Affected products

Apple iOS — versions unspecified
Apple Ipados
Apple Iphone OS
Apple macOS — versions unspecified
Apple Mac OS X
Apple tvOS — versions unspecified

Weakness classification (CWE)

CWE-120 — Buffer Copy without Checking Size of Input (Classic Buffer Overflow)

References

support.apple.com/kb/HT211289 (Vendor Advisory)
support.apple.com/kb/HT211288 (Vendor Advisory)
support.apple.com/kb/HT211290 (Vendor Advisory)

Frequently asked questions

What is CVE-2020-9940?: CVE-2020-9940 is a high-severity vulnerability in Apple iOS, classified under Buffer Copy without Checking Size of Input (Classic Buffer Overflow). CVSS score: 7.8/10. Published 2020-10-22.
How severe is CVE-2020-9940?: High severity. CVSS v3 base score is 7.8 out of 10.