๐Ÿ” CVE Alert

CVE-2026-63297

CRITICAL 9.9

Cross-project instance copy bypasses target project restrictions via TOCTOU in config merge

CVSS Score
9.9
EPSS Score
0.0%
EPSS Percentile
0th

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.

CWE CWE-367 CWE-863
Vendor canonical
Product lxd
Ecosystems
Industries
Technology
Published Aug 12, 2026
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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High

Affected Versions

Canonical / LXD
5.0.0 < 5.0.8 5.21.0 < 5.21.6

References

NVD โ†— CVE.org โ†— EPSS Data โ†—
github.com: https://github.com/canonical/lxd/security/advisories/GHSA-v989-qw7w-xvg4