This vulnerability in LXD occurs because restriction checks are performed before configuration merging is complete during cross-project instance copies. The timing flaw creates a TOCTOU race condition, enabling an attacker with authentication to bypass target project restrictions. By exploiting this, an attacker can copy instances containing disallowed high-privilege configurations into projects where such configurations should be blocked, effectively bypassing security policies.

Successful exploitation results in an attacker bypassing project-level restrictions to deploy instances with elevated privileges in restricted projects. This can lead to full compromise of the affected projects, including confidentiality, integrity, and availability impacts as indicated by the CVSS score of 9.9 (critical).

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. No official fix or temporary mitigation has been documented at this time. Until a patch is released, administrators should exercise caution when performing cross-project instance copies and consider restricting such operations to trusted users only.