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Critical

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

Type: advisorySources: OSV

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.

Products
Not specified
Affected versions
Not specified
Fixed versions
Not specified
CVEs
CVE-2026-63297
Confirmed fixed CVEs
Not specified
Updated in this feed
6 Nov 2026, 02:26 UTC · Revision 1

Source evidence

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

core-osv · Original source

Published 12 Aug 2026, 19:25 UTC

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.

osv:CVE-2026-63297
Complete source record
{
  "id": "3975cc2c3627ec52ddcae6845739d4e91848e78a71a5a37de5d248e0a3516060",
  "url": "https://osv.dev/vulnerability/CVE-2026-63297",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Cross-project instance copy bypasses target project restrictions via TOCTOU in config merge",
    "summary": "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.",
    "evidence": "osv:CVE-2026-63297",
    "products": [],
    "severity": "critical",
    "structured": {
      "id": "CVE-2026-63297",
      "aliases": [
        "CVE-2026-63297",
        "GHSA-v989-qw7w-xvg4"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/canonical/lxd",
              "type": "GIT",
              "events": [
                {
                  "introduced": "1e1349e3cbf30c1b2ce74e531d4dd0fd52c45be1"
                },
                {
                  "fixed": "58b58151cfc3bd9fb0fedce26fcdd73a3e67bdb8"
                },
                {
                  "introduced": "761d134ceabd306f57acfb0ca51f59b03751a5b0"
                },
                {
                  "fixed": "c6146714d0cacd04b77598bac149f5db714834f6"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "5.0.0"
                      },
                      {
                        "fixed": "5.0.8"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StandardRange"
                  },
                  {
                    "range": [
                      {
                        "introduced": "5.21.0"
                      },
                      {
                        "fixed": "5.21.6"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StandardRange"
                  }
                ]
              }
            }
          ],
          "versions": [
            "lxd-5.0.7",
            "lxd-5.21.5",
            "lxd-5.17",
            "lxd-5.16",
            "lxd-5.15",
            "lxd-5.14",
            "lxd-5.13",
            "lxd-5.12",
            "lxd-5.11",
            "lxd-5.0.2",
            "lxd-5.10",
            "lxd-5.9",
            "lxd-5.8",
            "lxd-5.7",
            "lxd-5.6",
            "lxd-5.5",
            "lxd-5.0.1",
            "lxd-5.4",
            "lxd-5.3",
            "lxd-5.2",
            "lxd-5.1",
            "lxd-5.0.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-63297.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:45.899833252Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/63xxx/CVE-2026-63297.json",
        "https://github.com/canonical/lxd/security/advisories/GHSA-v989-qw7w-xvg4",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-63297",
        "https://github.com/canonical/lxd"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-367",
          "CWE-863"
        ],
        "cna_assigner": "canonical",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/63xxx/CVE-2026-63297.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-63297",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 514263,
  "published_at": "2026-08-12T19:25:24.42+00:00"
}