CVE-2026-112480 in macOS
Summary
by MITRE • 10/26/2026
A permissions issue was addressed with additional restrictions. This issue is fixed in macOS Golden Gate 27.2, macOS Sequoia 15.8.2, macOS Tahoe 26.7.2. A user with screen sharing access may be able to view another user's screen.
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Analysis
by VulDB Data Team • 10/27/2026
The vulnerability described involves a critical permissions escalation flaw within the operating system’s remote desktop infrastructure, specifically affecting the Screen Sharing service in Apple macOS environments including versions such as Golden Gate 27.2, Sequoia 15.8.2, and Tahoe 26.7.2. This issue stems from an improper implementation of access control mechanisms that govern how user sessions are isolated during remote interaction. Under normal operational conditions, the operating system enforces strict boundaries between different user accounts to prevent unauthorized visibility into private desktop environments. However, due to a logic error in the permission validation process, these boundaries were insufficiently enforced when handling specific screen sharing requests or session states.
From a technical perspective, this flaw represents an authorization bypass where the system fails to correctly verify whether the initiating user has explicit rights to view the target user’s display output. Instead of relying solely on robust access control lists or capability-based security models that strictly limit resource visibility based on identity and role, the vulnerable implementation allowed certain authenticated users with basic screen sharing privileges to exploit a gap in session isolation logic. This likely occurs during the handshake phase of the VNC protocol integration used by macOS Screen Sharing, where state management errors permit one user’s graphical output buffer to be exposed to another user who should not have access. The root cause aligns closely with CWE-269 Improper Privilege Management and CWE-732 Incorrect Permission Assignment for Critical Resource, indicating that the system assigned broader read permissions than intended for sensitive display resources.
The operational impact of this vulnerability is significant in multi-user environments such as corporate workstations, educational labs, or shared development machines where multiple individuals may have legitimate but limited access rights. An attacker with local network access and valid credentials on a separate account could potentially view the screen activity of another user without their knowledge or consent. This capability enables unauthorized surveillance of sensitive information including passwords being typed, confidential documents displayed, financial data accessed, or proprietary code reviewed during development sessions. In high-security contexts, this constitutes a severe confidentiality breach that undermines trust in the operating system’s ability to maintain session isolation and protect user privacy against lateral movement within the same host machine.
This vulnerability maps directly to MITRE ATT&CK technique T1021 Remote Services, specifically under sub-techniques related to VNC or Apple Screen Sharing abuse, as well as T1537 Transfer Data to Cloud Account if exfiltration were combined with other tools, though the primary concern here is local data exposure. It also relates to T1046 Network Service Discovery in scenarios where attackers probe for active sharing sessions before attempting exploitation. The flaw highlights the importance of rigorous input validation and strict enforcement of least-privilege principles even within trusted internal networks, as local privilege escalation or cross-user spying can occur without elevated system rights initially required by traditional malware models.
Mitigation strategies primarily involve applying the provided software updates immediately to patch the underlying permission logic errors in the Screen Sharing service. Administrators should ensure that all endpoints running affected macOS versions are updated to at least Golden Gate 27.2, Sequoia 15.8.2, or Tahoe 26.7.2 respectively. Beyond patching, organizations should review and restrict screen sharing permissions through system preferences, granting access only to explicitly authorized users rather than relying on default broad-access configurations where applicable. Additionally, implementing network segmentation can limit the attack surface by preventing unauthorized devices from reaching systems with active remote services. Security monitoring tools should be configured to detect unusual patterns of VNC connection attempts or unexpected graphical buffer accesses that may indicate exploitation activity in real time.