CVE-2026-43809: Apple macOS out-of-bounds read system termination

Executive brief

A vulnerability in macOS could allow a malicious application to cause the computer to crash or shut down unexpectedly. This affects several versions of the Mac operating system, including Sequoia, Sonoma, and Tahoe. Users should update their systems to the latest available versions to prevent potential service disruptions.

Technical details

An out-of-bounds read vulnerability exists in macOS Sequoia, Sonoma, and Tahoe. The issue was caused by insufficient bounds checking, which could be triggered by a malicious application. Successful exploitation allows an attacker to cause a denial-of-service (DoS) condition via unexpected system termination. Apple has addressed this issue by improving bounds checking in macOS Sequoia 15.7.8, macOS Sonoma 14.8.8, and macOS Tahoe 26.6.

Affected products

• Apple macOS Sequoia Before 15.7.8
• Apple macOS Sonoma Before 14.8.8
• Apple macOS Tahoe Before 26.6

Timeline

• 2026-07-27: disclosed
• 2026-07-27: patched

References

• https://support.apple.com/en-us/128067
• https://support.apple.com/en-us/128071
• https://support.apple.com/en-us/128072