CVE-2026-7574 affects Anthropic Claude Desktop Cowork by failing to verify the integrity of the VM root filesystem image before booting. The product validates only the presence of the rootfs.img file and a version marker string but does not perform content integrity checks. This allows a local attacker with unprivileged code execution on the macOS host user account to modify the VM image, resulting in persistent arbitrary code execution within the VM environment and unauthorized access to host-mounted directories. The vulnerability is confirmed in version 1.1348.0 and related versions up to 1.2278.0. No official patch or remediation has been documented as of the published date.

A local attacker with unprivileged access to the victim macOS user account can modify the VM root filesystem image to execute arbitrary code persistently within the VM. This also enables the attacker to access directories mounted from the host system, potentially leading to data compromise and further system intrusion. The vulnerability compromises confidentiality, integrity, and availability within the affected VM environment.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, restrict local user access to prevent unauthorized modification of the VM root filesystem image. Monitor for updates from Anthropic regarding patches or mitigations addressing this integrity verification issue.