What is CVE-2026-43809?

CVE-2026-43809 is a critical-severity vulnerability in Apple Macos, classified under Out-of-bounds Read. CVSS score: 9.8/10. Published 2026-07-27.

How severe is CVE-2026-43809?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Out-of-bounds Read in Apple Macos

CVE-2026-43809

An out-of-bounds read was addressed with improved bounds checking. This issue is fixed in macOS Sequoia 15.7.8, macOS Sonoma 14.8.8, macOS Tahoe 26.6. An app may be able to cause unexpected system termination.

Vulnerability class: Buffer Overflow

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Apple Macos — versions 0

Weakness classification (CWE)

CWE-125 — Out-of-bounds Read

References

product-security@apple.com (Release Notes, Vendor Advisory)
product-security@apple.com (Release Notes, Vendor Advisory)
product-security@apple.com (Release Notes, Vendor Advisory)

Frequently asked questions

What is CVE-2026-43809?: CVE-2026-43809 is a critical-severity vulnerability in Apple Macos, classified under Out-of-bounds Read. CVSS score: 9.8/10. Published 2026-07-27.
How severe is CVE-2026-43809?: Critical severity. CVSS v3 base score is 9.8 out of 10.