CVE-2026-63300
Cross-project instance move bypasses all project restrictions allowing host command execution
Description
An improper validation vulnerability in the instancePostMigration function in lxd/instance_post.go of LXD allows an authenticated attacker with can_create_instances permissions on a restricted project to bypass project-level security restrictions. When migrating an instance between projects, LXD fails to validate the instance's configuration against the target project's enforced restrictions (such as restricted.containers.lowlevel, restricted.devices.*, and restricted.networks.access). An attacker can exploit this by creating a disallowed or high-privilege instance in an unrestricted project and subsequently moving it into the restricted project.
INFO
Published Date :
Aug. 12, 2026, 8:17 p.m.
Last Modified :
Aug. 28, 2026, 3:24 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | CRITICAL | cc1ad9ee-3454-478d-9317-d3e869d708bc | ||||
| CVSS 3.1 | CRITICAL | [email protected] | ||||
| CVSS 3.1 | CRITICAL | MITRE-CVE |
Solution
- Update LXD to the latest version.
- Verify project restrictions are enforced post-migration.
- Review instance migration security controls.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-63300.
| URL | Resource |
|---|---|
| https://github.com/canonical/lxd/pull/18605 | |
| https://github.com/canonical/lxd/pull/18651 | |
| https://github.com/canonical/lxd/security/advisories/GHSA-5g5r-wh97-qcq2 |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-63300 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-63300
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-63300 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-63300 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Aug. 13, 2026
Action Type Old Value New Value Changed SSVC {'id': 'CVE-2026-63300', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-08-12T00:00:00+00:00'} {'id': 'CVE-2026-63300', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-08-13T03:55:57.925616Z'} -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Aug. 13, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-63300', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-08-12T00:00:00+00:00'} -
New CVE Received by [email protected]
Aug. 12, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://github.com/canonical/lxd', 'vendor': 'Canonical', 'product': 'LXD', 'versions': [{'status': 'affected', 'version': '5.0.0', 'lessThan': '5.0.8', 'versionType': 'semver'}, {'status': 'affected', 'version': '5.21.0', 'lessThan': '5.21.6', 'versionType': 'semver'}, {'status': 'affected', 'version': '6.0', 'lessThan': '6.10', 'versionType': 'semver'}], 'platforms': ['Linux'], 'packageName': 'LXD', 'defaultStatus': 'unaffected'}] Added Description An improper validation vulnerability in the instancePostMigration function in lxd/instance_post.go of LXD allows an authenticated attacker with can_create_instances permissions on a restricted project to bypass project-level security restrictions. When migrating an instance between projects, LXD fails to validate the instance's configuration against the target project's enforced restrictions (such as restricted.containers.lowlevel, restricted.devices.*, and restricted.networks.access). An attacker can exploit this by creating a disallowed or high-privilege instance in an unrestricted project and subsequently moving it into the restricted project. Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H Added CWE CWE-862 Added Reference https://github.com/canonical/lxd/pull/18605 Added Reference https://github.com/canonical/lxd/pull/18651 Added Reference https://github.com/canonical/lxd/security/advisories/GHSA-5g5r-wh97-qcq2