First Background Security Improvement Released for macOS
Apple deploys BSI update fixing critical WebKit vulnerability CVE-2026-20643 that could allow Same Origin Policy bypass attacks.
macOS Tahoe 26.3.1 (a)
Background Security Improvement fixes WebKit vulnerability CVE-2026-20643. Studio Display support. New M5 Macs announced.
BSI Update: March 17, 2026 · macOS 26.3.1: March 4, 2026
⚠️ Important: macOS Tahoe 26 is the final macOS version to support Intel Macs. Future versions will require Apple Silicon.
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Troubleshooting GuidesApple deploys BSI update fixing critical WebKit vulnerability CVE-2026-20643 that could allow Same Origin Policy bypass attacks.
Update adds support for new Studio Display and Studio Display XDR, ships pre-installed on new M5 MacBook Air and MacBook Pro models.
Apple patches actively exploited zero-day vulnerability CVE-2026-20700, adds Liquid Glass interface options and enhanced parental controls.
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Background Security Improvement · WebKit vulnerability CVE-2026-20643 fix preventing Same Origin Policy bypass
Feature Update · Studio Display & Studio Display XDR support, ships with new M5 MacBooks
Critical Security Update · Patches CVE-2026-20700 zero-day exploit, Liquid Glass UI enhancements
Security Update · Important patches for all compatible Macs
Security Update · Essential security improvements