CVE-2026-112505 in macOS
Summary
by MITRE • 10/26/2026
An out-of-bounds write issue was addressed with improved bounds checking. This issue is fixed in macOS Golden Gate 27.2, macOS Sequoia 15.8.2, macOS Tahoe 26.7.2. A malicious Screen Sharing peer may be able to corrupt process memory.
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Analysis
by VulDB Data Team • 10/26/2026
The vulnerability described involves an out-of-bounds write condition within the Screen Sharing service on Apple operating systems including macOS Golden Gate 27.2, macOS Sequoia 15.8.2, and macOS Tahoe 26.7.2. This type of flaw typically arises when a program writes data to a memory location that falls outside the boundaries of an allocated buffer or array. In the context of Screen Sharing, which facilitates remote desktop access by allowing one user to control another Mac over a network connection, such a defect presents a significant security risk because it allows for arbitrary code execution if exploited successfully. The root cause is identified as insufficient bounds checking during the processing of data received from a peer device attempting to establish or maintain a screen sharing session.
From a technical perspective, out-of-bounds writes are particularly dangerous because they can overwrite adjacent memory structures that contain critical control information such as return addresses, function pointers, or exception handlers. When an attacker crafts malicious input specifically designed to trigger this buffer overflow condition, they can manipulate the program's execution flow. This manipulation enables the injection and subsequent execution of arbitrary code within the context of the affected process. Since Screen Sharing often runs with elevated privileges depending on system configuration and user permissions, successful exploitation could grant a remote attacker significant control over the target machine, potentially leading to full system compromise.
The operational impact of this vulnerability is severe due to its network-accessible nature. A malicious peer does not need physical access or prior authentication beyond what is required for screen sharing connections if proper security controls are misconfigured or bypassed through social engineering or credential theft. The ability to corrupt process memory means that an attacker could escalate privileges, install persistent malware, exfiltrate sensitive data visible on the shared screen, or use the compromised machine as a pivot point for further attacks within a network environment. This aligns with common attack patterns observed in remote access trojans and advanced persistent threat campaigns where initial access is gained through legitimate but vulnerable services.
Industry standards classify this type of vulnerability under CWE-787: Out-of-bounds Write, which highlights the failure to verify that memory writes remain within allocated boundaries. In terms of tactical mapping, exploitation scenarios involving remote code execution via network services often fall under MITRE ATT&CK techniques such as T1059 Command and Scripting Interpreter or T1203 Exploitation for Client Execution, depending on how the payload is delivered and executed post-exploitation. The fix implemented in the specified macOS versions addresses this by introducing rigorous bounds checking mechanisms that validate input data lengths against buffer capacities before processing occurs, thereby preventing any write operations from exceeding allocated memory limits.
To mitigate risks associated with similar vulnerabilities or while awaiting patch deployment where possible, organizations should enforce strict network segmentation to limit exposure of screen sharing services to untrusted networks. Additionally, disabling Screen Sharing when not in use reduces the attack surface significantly. Administrators must ensure that all macOS devices are updated to at least version 27.2 for Golden Gate, 15.8.2 for Sequoia, or 26.7.2 for Tahoe as these updates contain the necessary code changes to resolve the memory corruption issue. Regular auditing of remote access configurations and enforcing multi-factor authentication where supported can further reduce the likelihood of successful exploitation by unauthorized peers attempting to leverage this flaw.