CVE-2026-63297: An authorization bypass vulnerability in LXD due to a timing flaw during configuration merging allows an authenticated attacker to bypass target project…

PriorityP263critical9.9CVSS 3.1

AVNACLPRLUINSCCHIHAH

EPSS

0.20%

9.4th percentile

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.

Affected

2 ranges

Vendor	Product	Version range	Fixed in
canonical	lxd	>= 5.0.0 < 5.0.8	5.0.8
canonical	lxd	>= 5.21.0 < 5.21.6	5.21.6

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