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A researcher disclosed a three-bug macOS local privilege escalation chain that let an unprivileged user escalate to root, bypass System Integrity Protection (SIP), and ultimately achieve kernel code execution on systems before macOS 10.15.5. The first flaw was in authd, where Authorization Services trusted entitlement data returned by SecCodeCopySigningInformation without first validating the caller’s code signature, allowing forged entitlements such as com.apple.private.AuthorizationServices to unlock privileged authorization rights.
The chain then abused Apple-signed package installation through PackageKit and a vulnerable post-install script in macOSPublicBetaAccessUtility.pkg to execute code as root under system_installd, inheriting the com.apple.rootless.install.heritable entitlement and bypassing SIP. A third flaw in kextutil used a race condition to swap a verified Apple-signed kernel extension staged in /Library/StagedExtensions/private before loading; use of the -interactive flag made the race reliable enough to load malicious kernel code. The bugs were reported to Apple in 2020, and Apple addressed the issues in macOS 10.15.6 and tvOS 13.4.5, including a change so SecCodeCopySigningInformation verifies signatures directly.
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3 events from the most recent confirmed update back to the earliest known activity.
Before public disclosure, Apple shipped fixes for the reported vulnerabilities in macOS 10.15.6 and tvOS 13.4.5. Apple also mitigated the authd issue by changing SecCodeCopySigningInformation to verify signatures directly.
Neodyme publicly disclosed technical details of the three-bug 'Unauthd' chain, describing flaws in authd, PackageKit-related installation, and a kextutil race condition. The disclosure explained how the chain could achieve root access, bypass SIP, and load malicious kernel code on macOS versions earlier than 10.15.5.
Neodyme researcher Ilias reported a three-bug macOS exploit chain to Apple that enabled user-to-root escalation, a SIP bypass, and kernel code execution. The report was submitted on February 28, 2020.
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A race condition in Apple’s userspace entitlement and code-signing checks allowed local attackers to bypass authorization in privileged IPC services and escalate to root. Project Zero documented the underlying weakness as racy validation tied to process identity, while a later public write-up showed the issue in practice in `com.apple.appleseed.fbahelperd`, Apple’s privileged Feedback Assistant XPC service, tracked as **CVE-2019-8565**. The exploit abused PID reuse to impersonate a trusted client after the daemon validated the wrong process context, defeating entitlement checks that should have restricted access. Once inside the service, an attacker could invoke `copyLogFiles:` to copy arbitrary files through path traversal and chain additional helper behavior to achieve root code execution; Apple addressed the flaw in **macOS 10.14.4** and **iOS 12.2**, and researchers said the bug reinforced that PID-based authorization in macOS IPC should be replaced with audit-token-based validation.
Aug 1, 2026
Apple disclosed security fixes in **macOS Mojave 10.14.4**, **Security Update 2019-002 High Sierra**, and **Security Update 2019-002 Sierra** that addressed local privilege-escalation flaws in Time Machine diagnostic components. Public research later detailed a command injection bug, tracked as **`CVE-2019-8513`**, affecting macOS **10.12.x through 10.14.3**, where a local user could abuse the `timemachinehelper` XPC service and the `tmdiagnose` utility to execute arbitrary shell commands as **root**. The exploit reportedly worked by crafting a mounted disk image label so shell metacharacters were injected into a command built from `diskutil` output, ultimately yielding a root shell after diagnostic tasks completed. The same research also described a related arbitrary file overwrite issue in XPC helpers, assigned **`CVE-2019-8530`**, and noted it could previously be chained with an older `sudo` timestamp weakness; the findings echoed earlier public work on browser-to-system compromise and underscored how trusted macOS helper services could be leveraged for full system takeover.
Aug 1, 2026
Researchers disclosed the first public bypass of Apple **Memory Integrity Enforcement (MIE)** on macOS 26.4.1 by chaining two vulnerabilities: `CVE-2026-64704` in **SMBClient** and `CVE-2026-64699` in **webdavfs**. The SMB flaw is a type confusion issue triggered when a macOS client connects to a malicious SMB server, causing the kernel to reinterpret a Resolve ID context as a lease context and misuse attacker-influenced kernel pointers. The WebDAV flaw is a kernel memory disclosure bug triggered by a crafted HTTP `206` response from a malicious WebDAV server, leaking uninitialized kernel memory to userspace. The researchers said the combined exploit chain produces arbitrary kernel read/write primitives and ultimately kernel code execution, allowing an unprivileged user to escalate privileges to **root** despite Apple’s layered kernel protections. Apple has patched both issues in macOS 26.6, and the disclosure was accompanied by a public exploit-development challenge and notice of a planned Black Hat USA presentation detailing the technique.
Jul 30, 2026