CVE-2026-65405 Overview
CVE-2026-65405 is a memory initialization vulnerability affecting multiple Apple operating systems. The flaw allows a local application to determine kernel memory layout by reading uninitialized memory contents. Apple addressed the issue by improving memory handling in the affected kernel components. The vulnerability is classified as Use of Uninitialized Variable [CWE-457] and requires local access with user interaction to exploit. While the disclosure does not directly enable code execution, leaking kernel memory layout defeats Kernel Address Space Layout Randomization (KASLR) and can serve as a building block for chained exploits targeting privilege escalation or sandbox escape.
Critical Impact
A malicious application running locally on an affected Apple device can leak kernel memory layout information, undermining KASLR protections and enabling more reliable follow-on kernel exploitation.
Affected Products
- Apple iOS and iPadOS (fixed in 26.7 and 27)
- Apple macOS Sequoia 15.8, macOS Tahoe 26.7, and macOS Golden Gate 27
- Apple tvOS 27, visionOS 27, and watchOS 27
Discovery Timeline
- 2026-09-14 - CVE-2026-65405 published to the National Vulnerability Database
- 2026-09-16 - Last updated in NVD database
Technical Details for CVE-2026-65405
Vulnerability Analysis
The vulnerability stems from improper initialization of a memory region before it is returned to a user-space caller. When the kernel allocates a buffer and populates it without zeroing or fully overwriting every byte, residual data from prior kernel allocations remains readable. An unprivileged application can request the affected kernel interface, receive the response, and inspect the residual bytes for pointers, offsets, or structure fields that reveal the kernel's runtime memory layout.
Exploitation requires local code execution on the device and some form of user interaction, according to the disclosed attack profile. The confidentiality impact is high because kernel pointers and layout information are highly sensitive. There is no direct integrity or availability impact from this specific flaw.
Root Cause
The underlying defect is a Use of Uninitialized Variable weakness [CWE-457]. Kernel code paths returned data structures to user space without ensuring the full extent of the allocation was populated with intended values. Apple's fix applies improved memory handling, which typically means explicit zero-initialization of buffers or narrowing the copy length to only the fields actually written.
Attack Vector
An attacker must first deliver and run a malicious application on the target device. The application then invokes the vulnerable kernel interface and parses returned buffers for kernel addresses. Recovered pointers can be used to compute the KASLR slide and enable reliable exploitation of a separate memory corruption bug. No network access is required, and no elevated privileges are needed on the calling process.
No verified proof-of-concept code has been published for CVE-2026-65405. See the Apple security advisories for vendor-provided technical context.
Detection Methods for CVE-2026-65405
Indicators of Compromise
- No public indicators of compromise have been published for CVE-2026-65405 as of the last NVD update.
- Presence of unsigned or unexpected third-party applications on managed Apple devices should be treated as suspicious, particularly on devices running pre-patch OS builds.
Detection Strategies
- Inventory Apple endpoints and flag any device running iOS, iPadOS, macOS, tvOS, visionOS, or watchOS versions older than the fixed releases listed in Apple's advisories.
- Monitor mobile device management (MDM) telemetry for OS version drift and enforce automatic update policies on managed fleets.
- Correlate application installation events with subsequent anomalous process behavior, since kernel infoleaks are typically staged as part of a larger exploit chain.
Monitoring Recommendations
- Ingest Apple device compliance and OS build telemetry into your SIEM to identify unpatched hosts at scale.
- Track application entitlements and code-signing anomalies on macOS endpoints, particularly binaries invoking low-level kernel interfaces.
- Review crash reports and kernel panic logs for patterns consistent with kernel exploitation attempts following infoleak reconnaissance.
How to Mitigate CVE-2026-65405
Immediate Actions Required
- Update all Apple devices to the fixed OS versions: iOS 26.7, iPadOS 26.7, iOS 27, iPadOS 27, macOS Golden Gate 27, macOS Sequoia 15.8, macOS Tahoe 26.7, tvOS 27, visionOS 27, and watchOS 27.
- Enforce automatic OS updates through MDM policies to reduce exposure windows on fleet devices.
- Restrict installation of untrusted applications on managed endpoints and require notarization on macOS.
Patch Information
Apple has released security updates addressing CVE-2026-65405 across its operating system lineup. Refer to the vendor advisories for detailed build numbers and affected components: Apple Support Article #149034, Apple Support Article #149035, Apple Support Article #149036, Apple Support Article #149037, Apple Support Article #149038, Apple Support Article #149041, Apple Support Article #149042, and Apple Support Article #149043.
Workarounds
- No vendor-supplied workarounds exist; patching is the only supported remediation.
- Reduce risk by limiting application installation sources to the App Store or notarized developers and by removing unused or untrusted applications.
- Apply the principle of least privilege for user accounts on shared macOS systems to limit the impact of any locally executed malicious application.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
