Critical Flaw in Parallels Desktop Allows Local Users to Gain Root Access on Macs

SAN FRANCISCO — A critical security vulnerability discovered in Parallels Desktop for Mac allows non-administrator local users to gain full root access on affected systems, posing a significant risk to data integrity and system control. The flaw, identified by Yuval Moravchick of JFrog, stems from a misconfiguration in a background service socket that was set to world-writable permissions.

The vulnerability enables attackers with local user privileges to execute arbitrary code as the root user through command injection during the tar unpacking process. This mechanism allows malicious actors to bypass standard security boundaries and compromise the entire host operating system, potentially accessing sensitive files, installing persistent malware, or monitoring user activity without detection.

Parallels Desktop, a widely used virtualization software that enables Mac users to run Windows and other operating systems, confirmed the issue on September 16, 2026. The company released an emergency patch to address the socket misconfiguration and close the injection vector. However, the remediation effort faces a significant limitation: the fix is currently incompatible with Mac computers powered by Intel processors.

While Apple Silicon-based Macs can immediately install the security update, users on Intel-based machines remain exposed to the exploit until a compatible patch is developed and distributed. This creates a distinct disparity in security posture across the Mac user base, leaving a substantial segment of the market vulnerable in the interim. Security experts warn that attackers could target these unpatched systems specifically, knowing they lack immediate protection.

The discovery highlights the complexity of managing virtualization environments where host and guest operating systems share underlying resources. The world-writable socket allowed unauthorized interaction with the service responsible for handling file archives, turning a routine unpacking operation into a vector for privilege escalation. Once exploited, an attacker could theoretically take complete control of the physical Mac hardware, regardless of the user's initial permission level.

Parallels has urged all users to update their software immediately if their system supports the patch. For Intel Mac owners, the company is working on a solution but has not provided a timeline for when the fix will be available. In the meantime, security analysts recommend that users on affected Intel systems avoid running untrusted code or accessing suspicious files within the virtualization environment.

The situation remains fluid as developers race to finalize a patch for Intel architectures. Until then, the vulnerability represents an active threat vector for local attackers who can physically access or remotely compromise a standard user account on these machines. The broader implications for enterprise environments relying on Parallels Desktop for legacy Windows applications remain under assessment as organizations evaluate their exposure.