Integer overflow in Apple macOS
CVE-2026-20639
An integer overflow was addressed with improved input validation. This issue is fixed in macOS Sequoia 15.7.5, macOS Sonoma 14.8.5, macOS Tahoe 26.3. Processing a maliciously crafted string may lead to heap corruption.
Vulnerability class: Integer Overflow
Published · last modified .
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:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.006 (46.5th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 47th percentile — 46.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: 0.000
Affected products
- Apple macOS — versions 0
Weakness classification (CWE)
References
- support.apple.com/en-us/126348 (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-2026-20639?
- CVE-2026-20639 is a high-severity vulnerability in Apple macOS, classified under Integer Overflow or Wraparound. CVSS score: 7.5/10. Published 2026-03-25.
- How severe is CVE-2026-20639?
- High severity. CVSS v3 base score is 7.5 out of 10.