What is CVE-2026-39870?

CVE-2026-39870 is a high-severity vulnerability in Apple macOS, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 7.5/10. Published 2026-05-11.

How severe is CVE-2026-39870?

High severity. CVSS v3 base score is 7.5 out of 10.

Buffer overflow in Apple macOS

CVE-2026-39870

The issue was addressed with improved memory handling. This issue is fixed in macOS Sequoia 15.7.7, macOS Sonoma 14.8.7, macOS Tahoe 26.5. Processing a maliciously crafted image may corrupt process memory.

Vulnerability class: Buffer Overflow

Published 2026-05-11 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N.

EPSS exploit prediction

EPSS: 0.004 (36.0th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 36th percentile — 36.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.003 · newest: 0.004 · change: +0.001

Affected products

Apple macOS — versions 0

Weakness classification (CWE)

CWE-119 — Improper Restriction of Operations within the Bounds of a Memory Buffer

References

support.apple.com/en-us/127115 (Release Notes, Vendor Advisory)
support.apple.com/en-us/127116 (Release Notes, Vendor Advisory)
support.apple.com/en-us/127117 (Release Notes, Vendor Advisory)

Frequently asked questions

What is CVE-2026-39870?: CVE-2026-39870 is a high-severity vulnerability in Apple macOS, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 7.5/10. Published 2026-05-11.
How severe is CVE-2026-39870?: High severity. CVSS v3 base score is 7.5 out of 10.