CVE-2026-86986 in iOS
Summary
by MITRE • 10/26/2026
A use-after-free issue was addressed with improved memory management. This issue is fixed in Safari 27.2, iOS 26.7.2 and iPadOS 26.7.2, iOS 27.2 and iPadOS 27.2, macOS Golden Gate 27.2, visionOS 27.2. Processing maliciously crafted web content may lead to an unexpected Safari crash.
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Analysis
by VulDB Data Team • 10/27/2026
The vulnerability described is a classic use-after-free error, which falls under the Common Weakness Enumeration category CWE-416. This type of memory management flaw occurs when software continues to use a pointer after it has been freed or deallocated from its original location in memory. In the context of web browsers like Safari, this typically happens during the processing of complex web content where objects are dynamically allocated and released based on user interactions or script execution. When an application fails to properly manage these object lifecycles, it may retain a reference to memory that has already been returned to the system allocator. If another part of the program subsequently allocates new data into that same freed memory block before the old pointer is nullified or invalidated, the original code will inadvertently operate on the new data rather than its intended target. This mismatch leads to undefined behavior, which often manifests as application crashes but can potentially be exploited for more severe security breaches such as arbitrary code execution if an attacker can carefully control the contents of the newly allocated memory block.
The operational impact of this vulnerability is primarily observed as a denial of service through unexpected browser crashes when processing maliciously crafted web content. An attacker could host or distribute a webpage containing specially constructed JavaScript, HTML, or CSS that triggers the specific sequence of allocation and deallocation required to exploit the flaw. Upon visiting such a page, Safari would attempt to access memory it no longer owns, resulting in an immediate termination of the browser process. While this primarily affects availability by disrupting the user's browsing session, use-after-free vulnerabilities are historically among the most dangerous web-based attack vectors because they provide attackers with a mechanism to manipulate program flow and memory state. The potential for privilege escalation or remote code execution exists if the vulnerability can be chained with other weaknesses or if the browser sandboxing mechanisms fail to contain the exploit within isolated processes.
Apple has addressed this issue by implementing improved memory management practices within Safari and related operating system components including iOS, iPadOS, macOS Golden Gate, and visionOS versions 27.2 and later. The fix likely involves ensuring that pointers are properly nullified after deallocation or introducing safeguards such as guard bytes to detect access to freed memory during development and testing phases. These improvements align with secure coding standards recommended by industry bodies like the OWASP Foundation for preventing memory corruption vulnerabilities. Users should update their devices immediately to mitigate this risk, as unpatched versions remain susceptible to exploitation via malicious web content. Additionally, enabling features such as Content Security Policy headers on websites can help reduce the attack surface by restricting how scripts interact with page elements, thereby lowering the likelihood of triggering similar flaws in older or unpatched software instances.