CVE-2026-63297
Received
Received - Intake
LXD Authorization Bypass via TOCTOU in Cross-Project Instance Copies
Vulnerability report for CVE-2026-63297, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-08-12
Last updated on: 2026-08-12
Assigner: Canonical Ltd.
Description
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.
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| ubuntu | lxd | * |
| canonical | lxd | From 5.0.0 (inc) to 6.9 (exc) |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-367 | The product checks the state of a resource before using that resource, but the resource's state can change between the check and the use in a way that invalidates the results of the check. |
| CWE-863 | The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check. |
