CVE-2026-64779 in iOS
Summary
by MITRE • 08/18/2026
A memory corruption vulnerability was addressed with improved locking. This issue is fixed in iOS 18.7.10 and iPadOS 18.7.10, iOS 26.6.1 and iPadOS 26.6.1, macOS Tahoe 26.6.2. Processing maliciously crafted web content may lead to an unexpected Safari crash.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 08/18/2026
The vulnerability described involves a memory corruption flaw within the Safari browser engine, specifically related to improper handling of synchronization primitives during the processing of web content. Memory corruption issues are among the most critical classes of software defects because they can destabilize application execution and potentially allow for arbitrary code execution if exploited correctly. In this specific instance, the root cause was identified as a race condition or insufficient locking mechanism within the memory management subsystems that handle complex web page structures. When Safari processes maliciously crafted HTML, CSS, JavaScript, or other web technologies, it allocates and manages various data structures in memory. The lack of adequate synchronization allowed for concurrent access to these resources without proper mutual exclusion, leading to a state where memory pointers could be invalidated, overwritten, or accessed after being freed. This type of defect is commonly categorized under CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization, which highlights the failure to properly coordinate simultaneous operations on shared data structures.
The operational impact of this vulnerability manifests primarily as a denial of service condition for end users. As noted in the advisory, processing maliciously crafted web content leads to an unexpected crash of the Safari application. While crashes are often viewed merely as stability issues, memory corruption vulnerabilities carry significant security implications beyond simple availability loss. An attacker who can induce such a state might potentially manipulate the program counter or stack pointers through carefully constructed heap layouts, although in this specific report, the primary observed effect is the abrupt termination of the browser process. This crash prevents users from accessing legitimate web content and disrupts their workflow. Furthermore, repeated crashes can degrade system performance by consuming resources to restart processes or trigger diagnostic logging mechanisms. The vulnerability affects multiple Apple platforms including iOS 18.7.10, iPadOS 18.7.10, iOS 26.6.1, iPadOS 26.6.1, and macOS Tahoe 26.6.2, indicating that the underlying rendering engine or JavaScriptCore component shares similar architectural flaws across these operating systems.
From a threat modeling perspective, this vulnerability aligns with techniques observed in advanced persistent threats where attackers use malicious websites to exploit browser vulnerabilities for initial access or lateral movement within an enterprise environment. Although the immediate result is a crash, sophisticated exploitation attempts might leverage memory corruption states to achieve code execution, which would fall under ATT&CK technique T1203: Exploitation for Client Execution. The fact that the issue was addressed with improved locking suggests that Apple engineers identified specific critical sections in the web content processing pipeline where race conditions were occurring. By enforcing stricter synchronization protocols, such as mutexes or atomic operations, the system ensures that only one thread can modify shared memory structures at a time, thereby preventing the inconsistent states that lead to corruption and crashes.
To mitigate this vulnerability, users must ensure their devices are updated to the specified patched versions: iOS 18.7.10, iPadOS 18.7.10, iOS 26.6.1, iPadOS 26.6.1, or macOS Tahoe 26.6.2. These updates contain the necessary code changes that resolve the locking deficiencies within Safari’s web content processing engine. Until these patches are applied, users should exercise caution when visiting untrusted websites or clicking on links from unknown sources, as such interactions could trigger the vulnerability and result in service disruption. Additionally, enabling features like Content Security Policy (CSP) reporting can help organizations monitor for attempts to exploit similar vulnerabilities by detecting anomalous script executions or resource loads that deviate from expected behavior patterns. Regular patch management remains the most effective defense against known memory corruption flaws, as it ensures that synchronization improvements and other security hardening measures are actively enforced in production environments.