Out-of-bounds Read in Apple macOS
CVE-2026-20679
The issue was addressed with improved checks. This issue is fixed in macOS Sequoia 15.7.5, macOS Sonoma 14.8.5, macOS Tahoe 26.4. Processing a maliciously crafted file may lead to unexpected app termination.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L.
EPSS exploit prediction
EPSS: 0.004 (27.2th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 27th percentile — 27.2% 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: 0.004 · change: +0.001
Affected products
Weakness classification (CWE)
References
- support.apple.com/en-us/126794 (Release Notes, Vendor Advisory)
- support.apple.com/en-us/126795 (Release Notes, Vendor Advisory)
- support.apple.com/en-us/126796 (Release Notes, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-20679?
- CVE-2026-20679 is a medium-severity vulnerability in Apple macOS, classified under Out-of-bounds Read. CVSS score: 4.3/10. Published 2026-08-21.
- How severe is CVE-2026-20679?
- Medium severity. CVSS v3 base score is 4.3 out of 10.