CVE-2026-43748 in macOS
Summary
by MITRE • 07/28/2026
An out-of-bounds write issue was addressed with improved bounds checking. This issue is fixed in macOS Sequoia 15.7.8, macOS Tahoe 26.6. An app may be able to cause unexpected system termination.
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Analysis
by VulDB Data Team • 07/28/2026
This vulnerability represents a critical memory safety issue that could potentially allow malicious applications to crash system processes or cause unexpected termination of running applications. The out-of-bounds write flaw occurs when an application attempts to write data beyond the allocated memory boundaries of a buffer or array, which can result in corruption of adjacent memory regions and unpredictable system behavior. Such vulnerabilities are particularly dangerous because they can be exploited to execute arbitrary code or escalate privileges, making them a primary target for attackers seeking to compromise system integrity.
The technical nature of this issue falls under the category of memory corruption vulnerabilities that are commonly classified as CWE-787 - "Out-of-bounds Write" within the Common Weakness Enumeration framework. This particular flaw demonstrates poor bounds checking implementation where applications fail to properly validate memory access boundaries before writing data, creating opportunities for attackers to manipulate memory layout and potentially execute malicious payloads through carefully crafted inputs. The vulnerability affects Apple's operating system ecosystem specifically, with the patch being included in macOS Sequoia 15.7.8 and macOS Tahoe 26.6 releases, indicating that these versions contain improved memory validation mechanisms.
The operational impact of this vulnerability extends beyond simple application crashes to potentially compromise entire system stability and security posture. When an application triggers an out-of-bounds write condition, it can cause the operating system to terminate unexpectedly, leading to denial of service conditions where legitimate users lose access to their systems or applications. From an attacker perspective, this type of vulnerability can be leveraged in combination with other techniques to achieve privilege escalation or persistent system compromise, particularly when combined with techniques from the ATT&CK framework such as privilege escalation through memory corruption exploits.
The mitigation strategy for this vulnerability requires immediate deployment of the patched operating system versions mentioned in the release notes. System administrators should prioritize updating affected systems to macOS Sequoia 15.7.8 or macOS Tahoe 26.6 to ensure proper bounds checking mechanisms are in place. Additionally, organizations should implement comprehensive monitoring solutions to detect potential exploitation attempts and maintain regular security assessments to identify similar memory corruption vulnerabilities that may exist within their application environments. The fix demonstrates Apple's commitment to addressing memory safety issues through improved input validation and bounds checking implementations, aligning with industry best practices for preventing buffer overflow attacks and maintaining system integrity.