CVE-2026-86897: Apple Safari Information Disclosure Flaw

CVE-2026-86897 Overview

CVE-2026-86897 is a missing authorization vulnerability [CWE-862] affecting multiple Apple operating systems and the Safari browser. A malicious application installed on the device can bypass entitlement checks to access sensitive user data. Apple addressed the issue by adding additional entitlement checks across affected products. The flaw requires local access and user interaction, limiting remote exploitation scenarios but remaining relevant for supply-chain and malicious-app threat models.

Critical Impact
A locally installed app can access sensitive user data by circumventing entitlement enforcement across Safari, iOS, iPadOS, macOS, and visionOS.

Affected Products

Apple Safari (versions prior to 27)
Apple iOS and iPadOS (prior to 26.7 and 27)
Apple macOS (prior to Golden Gate 27) and Apple visionOS (prior to 27)

Discovery Timeline

2026-09-14 - CVE-2026-86897 published to NVD
2026-09-18 - Last updated in NVD database

Technical Details for CVE-2026-86897

Vulnerability Analysis

The vulnerability originates in Apple's entitlement enforcement logic, which authorizes app access to protected resources. Insufficient checks allowed an app running on the device to reach data reserved for higher-privileged or specifically entitled processes. Because the confidentiality impact is high while integrity and availability are unaffected, the flaw primarily enables data disclosure rather than tampering or service disruption. Exploitation is bounded to the local attack surface, requiring the malicious code to already run on the target device and involve user interaction such as launching the malicious app.

Root Cause

The root cause is a missing authorization check [CWE-862] in components shared across Safari and Apple operating systems. Apple's advisory notes the fix as adding "additional entitlement checks," indicating the original code path did not adequately verify that the calling process held the required entitlement before returning sensitive data.

Attack Vector

An attacker distributes a malicious application through sideloading, developer channels, or an approved distribution mechanism. When a user runs the app, it invokes the affected API path that fails to enforce entitlement checks. The app retrieves sensitive user data that should have been gated by authorization. No network access or elevated privileges are required, and no synthetic proof-of-concept code has been published for this issue.

See the Apple advisories for component-specific technical details: Apple Support Article 149034, Apple Support Article 149035, Apple Support Article 149038, Apple Support Article 149039, and Apple Support Article 149041.

Detection Methods for CVE-2026-86897

Indicators of Compromise

Applications requesting access to protected data classes without corresponding declared entitlements in their signed profiles.
Unexpected process reads against user data stores such as contacts, photos, location caches, or keychain-adjacent files from unsigned or newly installed apps.
Installation of apps from non-App Store sources shortly before anomalous data-access telemetry.

Detection Strategies

Inventory installed applications on managed macOS, iOS, iPadOS, and visionOS endpoints and correlate against known-good software baselines.
Monitor MDM signals for out-of-date OS builds still exposed to the vulnerability.
Review Safari version reporting from managed browsers to identify devices below Safari 27.

Monitoring Recommendations

Ingest MDM and endpoint telemetry into your SIEM to alert on Apple OS builds below the patched versions.
Track new application installs and code-signing anomalies on macOS through Endpoint Security Framework events.
Alert on sensitive data access from apps lacking corresponding entitlement declarations.

How to Mitigate CVE-2026-86897

Immediate Actions Required

Update all Apple devices to Safari 27, iOS 26.7 or 27, iPadOS 26.7 or 27, macOS Golden Gate 27, and visionOS 27.
Enforce OS and browser minimum-version compliance policies through your MDM.
Audit installed applications and remove untrusted or unnecessary third-party apps.

Patch Information

Apple released fixes across the affected product lines. Refer to the vendor advisories: Apple Support Article 149034, Apple Support Article 149035, Apple Support Article 149038, Apple Support Article 149039, and Apple Support Article 149041.

Workarounds

Restrict app installation to the App Store and vetted enterprise distribution channels until patches are applied.
Disable sideloading and developer-mode installations on managed devices where feasible.
Limit user access to sensitive data classes through MDM privacy preference policies.

bash

# Example MDM compliance check for minimum OS versions
# macOS
sw_vers -productVersion
# iOS/iPadOS (via profile)
# require: OSVersion >= 26.7
# Safari
defaults read /Applications/Safari.app/Contents/Info.plist CFBundleShortVersionString