What is CVE-2026-39877?

CVE-2026-39877 is a high-severity vulnerability in Apple Macos, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 7.8/10. Published 2026-07-27.

How severe is CVE-2026-39877?

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

Buffer overflow in Apple Macos

CVE-2026-39877

A memory corruption issue was addressed with improved memory handling. This issue is fixed in macOS Sequoia 15.7.8, macOS Sonoma 14.8.8. An app may be able to disclose kernel memory.

Vulnerability class: Buffer Overflow

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.

Affected products

Apple Macos — versions 0

Weakness classification (CWE)

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

References

product-security@apple.com
product-security@apple.com

Frequently asked questions

What is CVE-2026-39877?: CVE-2026-39877 is a high-severity vulnerability in Apple Macos, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 7.8/10. Published 2026-07-27.
How severe is CVE-2026-39877?: High severity. CVSS v3 base score is 7.8 out of 10.