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PatchSiren cyber security CVE debrief

CVE-2026-63299 Canonical CVE debrief

An authorization bypass vulnerability in LXD allows an authenticated user to bypass project-level disk and volume limits. Two related code paths fail to verify resource limits during volume operations: the storagePoolVolumeTypePostMove function omits the limits.AllowVolumeCreation check before moving a volume across projects, and volume snapshot restore operations skip the AllowVolumeUpdate check when the configuration is nil (Config == nil). An attacker can exploit these flaws to allocate storage resources that exceed the administrative limits configured for a project.

Vendor
Canonical
Product
LXD
CVSS
CRITICAL 9.9
CISA KEV
Not listed in stored evidence
Original CVE published
2026-08-12
Original CVE updated
2026-08-28
Advisory published
2026-08-12
Advisory updated
2026-08-28

Who should care

Administrators and users of LXD instances should be aware of this vulnerability and take steps to patch and monitor their systems. Additionally, security teams and vulnerability management teams should prioritize patching LXD instances to prevent potential storage resource exhaustion. Operators of LXD-based platforms and services should also review their configurations and ensure that project-level disk and volume limits are properly enforced.

Technical summary

The vulnerability allows an authenticated user to bypass project-level disk and volume limits in LXD. Two code paths fail to verify resource limits during volume operations, enabling an attacker to allocate excessive storage resources. This can lead to storage resource exhaustion and potential denial-of-service conditions. Administrators should be aware of the vulnerability's technical implications and take steps to patch and monitor their LXD instances.

Defensive priority

Administrators should prioritize patching LXD instances to prevent potential storage resource exhaustion.

Recommended defensive actions

  • Patch LXD instances to prevent potential storage resource exhaustion
  • Verify project-level disk and volume limits are properly configured
  • Monitor for suspicious volume operations
  • Review LXD project configurations for exposure
  • Check relevant monitoring, detection, and logs for exposed assets
  • Track exceptions and retest remediated assets
  • Confirm whether affected product deployments exist in managed environments

Evidence notes

The CVE Program record and NVD vulnerability detail provide official information about the vulnerability. However, the source detail is thin, and further verification is needed to confirm the affected scope and vendor remediation. To verify, defenders should review LXD project configurations, check for suspicious volume operations, and monitor system resource utilization. Additional information from LXD documentation and security advisories may be necessary to fully understand the vulnerability's impact.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-63299 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-63299

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-63299 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-63299

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.