What is CVE-2023-27939?

CVE-2023-27939 is a medium-severity vulnerability in Apple macOS, classified under Out-of-bounds Read. CVSS score: 5.5/10. Published 2023-08-14.

How severe is CVE-2023-27939?

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

Out-of-bounds Read in Apple macOS

CVE-2023-27939

An out-of-bounds read was addressed with improved input validation. This issue is fixed in macOS Ventura 13.3. Processing an image may result in disclosure of process memory.

Vulnerability class: Buffer Overflow

Published 2023-08-14 · 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:H/I:N/A:N.

EPSS exploit prediction

EPSS: 0.002 (12.7th percentile), scored 2026-10-03.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 13th percentile — 12.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: 0.000

Affected products

Apple macOS — versions unspecified

Weakness classification (CWE)

CWE-125 — Out-of-bounds Read

References

support.apple.com/en-us/HT213670 (Release Notes, Vendor Advisory)

Frequently asked questions

What is CVE-2023-27939?: CVE-2023-27939 is a medium-severity vulnerability in Apple macOS, classified under Out-of-bounds Read. CVSS score: 5.5/10. Published 2023-08-14.
How severe is CVE-2023-27939?: Medium severity. CVSS v3 base score is 5.5 out of 10.