CVE-2026-84527 Overview
CVE-2026-84527 is an information disclosure vulnerability affecting multiple Apple operating systems. The flaw stems from insufficient data redaction in system logs, allowing a local application to access sensitive user data written to log files. Apple addressed the issue by improving redaction of sensitive information before it is written to logs.
The vulnerability is classified under [CWE-532] (Insertion of Sensitive Information into Log File). Exploitation requires local access and user interaction, and there is no evidence of exploitation in the wild.
Critical Impact
A malicious app installed on an affected Apple device can read sensitive user data leaked into system logs, enabling data harvesting without triggering standard permission prompts.
Affected Products
- Apple iOS and iPadOS (fixed in iOS 27 and iPadOS 27)
- Apple macOS (fixed in macOS Golden Gate 27, macOS Sequoia 15.8, macOS Tahoe 26.7)
- Apple tvOS 27, visionOS 27, and watchOS 27
Discovery Timeline
- 2026-09-14 - CVE-2026-84527 published to the National Vulnerability Database (NVD)
- 2026-09-18 - Last updated in NVD database
Technical Details for CVE-2026-84527
Vulnerability Analysis
The vulnerability resides in Apple platform logging subsystems that fail to fully redact sensitive user data before persisting log entries. Log data on Apple platforms can be read by applications or processes with access to the unified logging store, meaning any data written without proper redaction becomes accessible to a broader trust boundary than intended.
An application running on the device can query the logs and retrieve values that should have been filtered as <private>. Depending on which subsystem produced the log entry, the exposed data may include identifiers, tokens, or other user attributes.
Root Cause
The root cause is missing or incomplete application of Apple's log redaction annotations for fields containing sensitive user data. When developers or system components fail to mark log format specifiers as private, the logging framework writes the raw values to persistent log storage. Apple's fix improves the redaction logic so that these values are omitted or masked.
Attack Vector
Exploitation requires a local application on the target device and user interaction to install or run that application. Once running, the app reads the unified log store or diagnostic archives to harvest the unredacted sensitive fields. Network access, elevated privileges, and kernel-level access are not required, which lowers the exploitation barrier for malicious apps distributed through sideloading, developer profiles, or supply-chain compromise.
No public proof-of-concept exploit code is available for CVE-2026-84527. Refer to the Apple support documents linked below for vendor-provided technical guidance.
Detection Methods for CVE-2026-84527
Indicators of Compromise
- Unexpected applications requesting or accessing diagnostic log data or sysdiagnose archives on macOS, iOS, or iPadOS endpoints.
- Anomalous invocations of log command-line utilities or OSLogStore APIs by non-diagnostic third-party apps.
- Outbound transfers of .logarchive bundles or compressed diagnostic exports from managed devices.
Detection Strategies
- Inventory installed applications across managed Apple devices and correlate against known-good publisher lists using mobile device management (MDM) telemetry.
- Monitor endpoint process telemetry for unauthorized use of logging APIs, particularly OSLogStore reads and Console app automation.
- Baseline diagnostic-file access patterns and alert on deviations, especially reads by user-installed applications.
Monitoring Recommendations
- Ingest macOS Endpoint Security Framework (ESF) events and unified log access events into a centralized SIEM for cross-fleet analysis.
- Track OS version compliance across the Apple fleet and alert on devices still running vulnerable builds after the patch deadline.
- Review third-party MDM and enterprise-signed application inventories for unnecessary logging or diagnostic entitlements.
How to Mitigate CVE-2026-84527
Immediate Actions Required
- Update all Apple devices to iOS 27, iPadOS 27, macOS Golden Gate 27, macOS Sequoia 15.8, macOS Tahoe 26.7, tvOS 27, visionOS 27, or watchOS 27.
- Enforce OS update compliance through MDM policies and block noncompliant devices from accessing sensitive corporate resources.
- Audit installed third-party applications and remove any that are unnecessary or from untrusted publishers.
Patch Information
Apple released fixes across its platform lineup in September 2026. Refer to the vendor advisories for build numbers and detailed release notes: Apple Support Document #149034, #149035, #149036, #149037, #149038, #149042, and #149043.
Workarounds
- Restrict application installation to the official App Store and remove sideloaded or enterprise-signed apps that are not business-critical.
- Disable or restrict configuration profiles that grant diagnostic or logging entitlements to third-party applications.
- Delete existing diagnostic log archives and sysdiagnose bundles from devices where feasible to reduce residual exposure of previously logged sensitive data.
# Example: Query current macOS build to verify patch status
sw_vers -productVersion
# Example: List recent sysdiagnose archives on macOS for review
ls -lah /var/tmp/sysdiagnose_*.tar.gz 2>/dev/null
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
