Local Privilege Escalation in Lima via Guest Agent Socket

Lima, a project providing Linux virtual machines on macOS, contains a vulnerability (CVE-2026-53657) affecting instances using the QEMU driver. An arbitrary user within the guest VM can access the guest agent Unix socket located at /run/lima-guestagent.sock. Because this socket provides tunneling services for arbitrary addresses, including those used by privileged system daemons like D-Bus, an unprivileged user can craft requests to execute arbitrary commands with root privileges within the guest instance. This issue is specific to the QEMU driver; the 'vz' driver is unaffected as it utilizes vsocks. The vulnerability is patched in Lima version 2.1.3.

Impact

The vulnerability allows for local privilege escalation (LPE) within the context of a Lima virtual machine. Successful exploitation grants an unprivileged guest user root-level command execution. The scope is limited to the VM instance itself and does not directly result in root access on the macOS host.

Recommendation

• Upgrade the Lima installation to version 2.1.3 or higher to address CVE-2026-53657.
• If upgrading is not immediately feasible, switch to the 'vz' driver for VM instances using 'limactl create --vm-type=vz' or disable the guest agent using the '--plain' flag during VM creation.
• Audit existing VM configurations to identify instances currently using the QEMU driver.