CVE-2026-63296 — Project restriction bypass via instance migration config override
An authorization bypass vulnerability in LXD allows an authenticated attacker to bypass target project restrictions during instance migration. When migrating an instance to a target project, LXD accepts configuration overrides without validating the new configuration against the target project's enforced restrictions. An attacker can exploit this flaw to move instances with disallowed high-privilege configurations into restricted projects, bypassing security controls.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- Technical severity (critical)+10
- CISA SSVC: exploitation "poc"+5
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
- Documented mitigation — github.com (NIST National Vulnerability Database)
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Canonical Lxd).
- Apply the documented mitigations until a definitive fix is available.
- Search available logs for exploit probes matching the vulnerability class (access control), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 9.9 | CVSS 3.1 | Critical | 3.1 | 6.0 | security@ubuntu.com via NIST National Vulnerability Database |
| 9.9 | CVSS 3.1 | Critical | — | — | canonical via CVE Program (cve.org) e CISA ADP |
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H (score shown at the top: security@ubuntu.com) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
- Audit administrative actions and access to resources outside each user’s normal pattern.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · canonical/lxd
- SSVC assessment updated
- Record published
- Fix documented
- CVSS changed · 9.9
- Source status changed · → Analyzed
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 15, 2026 – Oct 15, 2026
References
1 on the record
Elsewhere on this site
Related CVEs (same products)
- Critical CVE-2026-66897 Path Traversal in Canonical Lxd Aug 24, 2026
- Critical CVE-2026-66898 Path Traversal in Canonical Lxd Aug 12, 2026
- High CVE-2026-16033 Arbitrary file read+write on host via templates/ symlink in malicious image Aug 12, 2026
- Critical CVE-2026-63294 Root RCE via image backup.yaml symlink Aug 12, 2026
- Medium CVE-2026-63295 Project restriction `restricted.containers.privilege=isolated` bypassable by omitting `security.idmap.isolated` Aug 12, 2026
- Critical CVE-2026-63297 Cross-project instance copy bypasses target project restrictions via TOCTOU in config merge Aug 12, 2026
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No FIRST EPSS score.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-63296 is "Project restriction bypass via instance migration config override", rated Critical. It affects Lxd (Canonical); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 9.9 describes technical severity. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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