CVE-2026-63297

Description

An authorization bypass vulnerability in LXD due to a timing flaw during configuration merging allows an authenticated attacker to bypass target project restrictions during cross-project instance copies. When copying an instance to a target project, LXD performs restriction checks before configuration merging is complete, creating a time-of-check to time-of-use (TOCTOU) condition. An attacker can exploit this flaw to copy instances with disallowed high-privilege configurations into restricted projects, bypassing security controls.

Weakness classification

• security@ubuntu.com: CWE-367

Primary references

• security@ubuntu.com — Vendor Advisory, Exploit, Mitigation
• 134c704f-9b21-4f2e-91b3-4a467353bcc0 — Vendor Advisory, Exploit, Mitigation