CVE-2026-43688 in iOS
Summary
by MITRE • 09/14/2026
A memory corruption issue was addressed with improved input validation. This issue is fixed in iOS 27 and iPadOS 27, macOS Golden Gate 27. Processing a maliciously crafted file may lead to unexpected app termination.
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Analysis
by VulDB Data Team • 09/14/2026
The vulnerability described involves a critical memory corruption flaw within the operating systems of Apple devices, specifically affecting iOS 27, iPadOS 27, and macOS Golden Gate 27. This type of issue typically stems from improper handling of data structures in memory, where the application fails to correctly validate input before processing it. The root cause is identified as insufficient input validation, which allows a maliciously crafted file to trigger undefined behavior during execution. In software security terms, this aligns with CWE-120 Buffer Overflow or similar categories under CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer, depending on whether the corruption involves overwriting adjacent memory locations or corrupting heap metadata. The lack of rigorous boundary checks enables an attacker to manipulate how data is stored and accessed in RAM, leading to instability in the affected application.
From an operational perspective, the immediate impact of this vulnerability is denial of service through unexpected app termination. When a user processes a specially constructed file designed to exploit this flaw, the memory corruption causes the application to crash abruptly rather than handling the error gracefully or rejecting the input safely. While the primary observed effect is a crash, memory corruption vulnerabilities often carry higher risks beyond simple disruption. Depending on the specific nature of the overflow and the context in which the vulnerable code executes, such flaws can potentially be leveraged for arbitrary code execution if an attacker can control the overwritten data to redirect program flow or inject shellcode. However, based on the provided description, the confirmed impact is limited to application instability and termination, suggesting that mitigations like stack canaries or address space layout randomization may have partially neutralized more severe exploitation vectors, leaving only a denial-of-service outcome for now.
This vulnerability maps directly to ATT&CK technique T1496 Resource Hijacking under the sub-technique of Denial of Service via application crashes, as it disrupts normal operations by forcing processes to terminate unexpectedly. It also relates to CWE-20 Improper Input Validation, highlighting a failure in the software development lifecycle where edge cases involving malformed files were not adequately tested or sanitized before deployment. The presence of such flaws indicates that while basic functionality may work for standard inputs, the system lacks robustness against adversarial inputs designed specifically to trigger internal errors.
To mitigate this risk, users are strongly advised to update their devices immediately to iOS 27, iPadOS 27, or macOS Golden Gate 27, where Apple has implemented improved input validation mechanisms. These updates likely include stricter checks on file formats, enhanced bounds checking for memory operations, and potentially the use of safer programming constructs that prevent out-of-bounds writes. For developers integrating similar components in custom applications, it is essential to implement comprehensive input sanitization routines that validate data types, lengths, and structures before processing. Utilizing static analysis tools and fuzzing techniques during development can help identify such memory safety issues early. Additionally, enabling system-level protections like Data Execution Prevention (DEP) and Address Space Layout Randomization (ASLR) provides an additional layer of defense against potential exploitation attempts that might arise from similar vulnerabilities in other software components.