Vulnerability-Lookup

ubuntu-cve-2026-66897

Vulnerability from osv_ubuntu

Published

2026-08-24 10:16

Modified

2026-09-02 16:22

Summary

Details

A path traversal vulnerability in LXD's instance template processing allows an attacker with container edit permissions, or any user launching a crafted image, to overwrite arbitrary files on the host system as root. When processing target template paths specified in metadata.yaml, LXD validates the path against a confined os.Root directory handle but subsequently opens and creates the file using os.Create with an unconfined string path. This discrepancy between path resolution checks and file creation allows an attacker to escape directory confinement, overwrite root-owned host files, and achieve host root code execution.

Severity

9.9 (Critical)


                    
                      CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

N/A (UNKNOWN)


                    
                      medium

References

URL

Type

	https://ubuntu.com/security/CVE-2026-66897	REPORT
	https://www.cve.org/CVERecord?id=CVE-2026-66897	REPORT
	https://github.com/canonical/lxd/security/advisor…	REPORT

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "golang-github-lxc-lxd-dev",
            "binary_version": "2.0.11-0ubuntu1~16.04.4+esm3"
          },
          {
            "binary_name": "lxc2",
            "binary_version": "2.0.11-0ubuntu1~16.04.4+esm3"
          },
          {
            "binary_name": "lxd",
            "binary_version": "2.0.11-0ubuntu1~16.04.4+esm3"
          },
          {
            "binary_name": "lxd-client",
            "binary_version": "2.0.11-0ubuntu1~16.04.4+esm3"
          },
          {
            "binary_name": "lxd-tools",
            "binary_version": "2.0.11-0ubuntu1~16.04.4+esm3"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:16.04:LTS",
        "name": "lxd",
        "purl": "pkg:deb/ubuntu/lxd@2.0.11-0ubuntu1~16.04.4+esm3?arch=source\u0026distro=esm-infra-legacy/xenial"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.20-0ubuntu4",
        "0.21-0ubuntu3",
        "0.21-0ubuntu5",
        "0.22-0ubuntu1",
        "0.22-0ubuntu2",
        "0.23-0ubuntu1",
        "0.23-0ubuntu2",
        "0.23-0ubuntu3",
        "0.24-0ubuntu2",
        "0.24-0ubuntu3",
        "0.24-0ubuntu4",
        "0.25-0ubuntu1",
        "0.26-0ubuntu2",
        "0.26-0ubuntu3",
        "0.27-0ubuntu1",
        "0.27-0ubuntu2",
        "2.0.0~beta1-0ubuntu3",
        "2.0.0~beta1-0ubuntu4",
        "2.0.0~beta2-0ubuntu1",
        "2.0.0~beta2-0ubuntu2",
        "2.0.0~beta3-0ubuntu1",
        "2.0.0~beta3-0ubuntu2",
        "2.0.0~beta3-0ubuntu3",
        "2.0.0~beta3-0ubuntu4",
        "2.0.0~beta4-0ubuntu1",
        "2.0.0~beta4-0ubuntu2",
        "2.0.0~beta4-0ubuntu3",
        "2.0.0~beta4-0ubuntu4",
        "2.0.0~beta4-0ubuntu5",
        "2.0.0~beta4-0ubuntu6",
        "2.0.0~beta4-0ubuntu7",
        "2.0.0~rc1-0ubuntu1",
        "2.0.0~rc1-0ubuntu2",
        "2.0.0~rc1-0ubuntu3",
        "2.0.0~rc2-0ubuntu2",
        "2.0.0~rc2-0ubuntu3",
        "2.0.0~rc3-0ubuntu1",
        "2.0.0~rc3-0ubuntu2",
        "2.0.0~rc3-0ubuntu3",
        "2.0.0~rc3-0ubuntu4",
        "2.0.0~rc4-0ubuntu1",
        "2.0.0~rc5-0ubuntu1",
        "2.0.0~rc6-0ubuntu1",
        "2.0.0~rc6-0ubuntu2",
        "2.0.0~rc7-0ubuntu1",
        "2.0.0~rc7-0ubuntu2",
        "2.0.0~rc8-0ubuntu1",
        "2.0.0~rc8-0ubuntu2",
        "2.0.0~rc8-0ubuntu3",
        "2.0.0~rc8-0ubuntu5",
        "2.0.0~rc8-0ubuntu6",
        "2.0.0~rc8-0ubuntu7",
        "2.0.0~rc9-0ubuntu2",
        "2.0.0~rc9-0ubuntu3",
        "2.0.0~rc9-0ubuntu4",
        "2.0.0~rc9-0ubuntu5",
        "2.0.0-0ubuntu1",
        "2.0.0-0ubuntu2",
        "2.0.0-0ubuntu3",
        "2.0.0-0ubuntu4",
        "2.0.1-0ubuntu1~16.04.1",
        "2.0.2-0ubuntu1~16.04.1",
        "2.0.3-0ubuntu1~ubuntu16.04.2",
        "2.0.4-0ubuntu1~ubuntu16.04.1",
        "2.0.5-0ubuntu1~ubuntu16.04.1",
        "2.0.8-0ubuntu1~ubuntu16.04.1",
        "2.0.8-0ubuntu1~ubuntu16.04.2",
        "2.0.9-0ubuntu1~16.04.1",
        "2.0.9-0ubuntu1~16.04.2",
        "2.0.10-0ubuntu1~16.04.1",
        "2.0.10-0ubuntu1~16.04.2",
        "2.0.11-0ubuntu1~16.04.2",
        "2.0.11-0ubuntu1~16.04.4",
        "2.0.11-0ubuntu1~16.04.4+esm1",
        "2.0.11-0ubuntu1~16.04.4+esm2",
        "2.0.11-0ubuntu1~16.04.4+esm3"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "lxd",
            "binary_version": "3.0.3-0ubuntu1~18.04.2+esm3"
          },
          {
            "binary_name": "lxd-client",
            "binary_version": "3.0.3-0ubuntu1~18.04.2+esm3"
          },
          {
            "binary_name": "lxd-tools",
            "binary_version": "3.0.3-0ubuntu1~18.04.2+esm3"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:18.04:LTS",
        "name": "lxd",
        "purl": "pkg:deb/ubuntu/lxd@3.0.3-0ubuntu1~18.04.2+esm3?arch=source\u0026distro=esm-infra/bionic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2.18-0ubuntu6",
        "2.19-0ubuntu1",
        "2.20-0ubuntu3",
        "2.20-0ubuntu4",
        "2.21-0ubuntu1",
        "2.21-0ubuntu2",
        "2.21-0ubuntu3",
        "2.21-0ubuntu4",
        "3.0.0~beta2-0ubuntu3",
        "3.0.0~beta3-0ubuntu3",
        "3.0.0~beta5-0ubuntu2",
        "3.0.0~beta7-0ubuntu1",
        "3.0.0-0ubuntu1",
        "3.0.0-0ubuntu2",
        "3.0.0-0ubuntu3",
        "3.0.0-0ubuntu4",
        "3.0.1-0ubuntu1~18.04.1",
        "3.0.2-0ubuntu1~18.04.1",
        "3.0.3-0ubuntu1~18.04.1",
        "3.0.3-0ubuntu1~18.04.2",
        "3.0.3-0ubuntu1~18.04.2+esm1",
        "3.0.3-0ubuntu1~18.04.2+esm2",
        "3.0.3-0ubuntu1~18.04.2+esm3"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "lxd",
            "binary_version": "1:0.10"
          },
          {
            "binary_name": "lxd-client",
            "binary_version": "1:0.10"
          },
          {
            "binary_name": "lxd-tools",
            "binary_version": "1:0.10"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:20.04:LTS",
        "name": "lxd",
        "purl": "pkg:deb/ubuntu/lxd@1:0.10?arch=source\u0026distro=focal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1:0.7",
        "1:0.8",
        "1:0.9",
        "1:0.10"
      ]
    }
  ],
  "aliases": [],
  "details": "A path traversal vulnerability in LXD\u0027s instance template processing allows an attacker with container edit permissions, or any user launching a crafted image, to overwrite arbitrary files on the host system as root. When processing target template paths specified in metadata.yaml, LXD validates the path against a confined os.Root directory handle but subsequently opens and creates the file using os.Create with an unconfined string path. This discrepancy between path resolution checks and file creation allows an attacker to escape directory confinement, overwrite root-owned host files, and achieve host root code execution.",
  "id": "UBUNTU-CVE-2026-66897",
  "modified": "2026-09-02T16:22:32Z",
  "published": "2026-08-24T10:16:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-66897"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-66897"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/canonical/lxd/security/advisories/GHSA-q39m-8fx9-42fv"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2026-66897"
  ]
}

CVE-2026-66897 (GCVE-0-2026-66897)

Vulnerability from cvelistv5 – Published: 2026-08-24 09:08 – Updated: 2026-08-25 03:55

Title

Instance template path traversal allows arbitrary host file write as root

Summary

Severity

9.9 (Critical)


                        
                          CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

SSVC

Exploitation: none Automatable: no Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-08-24 00:00 UTC

CWE

CWE-22 - Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
CWE-23 - Relative Path Traversal

Assigner

canonical mitre root

References

1 reference

URL	Tags
https://github.com/canonical/lxd/security/advisor…	vdb-entryvendor-advisory

Impacted products

1 product

Vendor	Product	Version
Canonical	LXD	Affected: 4.0.0 , < 4.0.13 (semver) Affected: 5.0.0 , < 5.0.9 (semver) Affected: 5.21.0 , < 5.21.7 (semver) Affected: 6.0 , < 6.10 (semver)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-66897",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-08-24T00:00:00+00:00",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-08-25T03:55:49.930Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "packageName": "LXD",
          "platforms": [
            "Linux"
          ],
          "product": "LXD",
          "repo": "https://github.com/canonical/lxd",
          "vendor": "Canonical",
          "versions": [
            {
              "lessThan": "4.0.13",
              "status": "affected",
              "version": "4.0.0",
              "versionType": "semver"
            },
            {
              "lessThan": "5.0.9",
              "status": "affected",
              "version": "5.0.0",
              "versionType": "semver"
            },
            {
              "lessThan": "5.21.7",
              "status": "affected",
              "version": "5.21.0",
              "versionType": "semver"
            },
            {
              "lessThan": "6.10",
              "status": "affected",
              "version": "6.0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "A path traversal vulnerability in LXD\u0027s instance template processing allows an attacker with container edit permissions, or any user launching a crafted image, to overwrite arbitrary files on the host system as root. When processing target template paths specified in metadata.yaml, LXD validates the path against a confined os.Root directory handle but subsequently opens and creates the file using os.Create with an unconfined string path. This discrepancy between path resolution checks and file creation allows an attacker to escape directory confinement, overwrite root-owned host files, and achieve host root code execution."
        }
      ],
      "impacts": [
        {
          "capecId": "CAPEC-126",
          "descriptions": [
            {
              "lang": "en",
              "value": "Path Traversal"
            }
          ]
        },
        {
          "capecId": "CAPEC-153",
          "descriptions": [
            {
              "lang": "en",
              "value": "Input Data Manipulation"
            }
          ]
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 9.9,
            "baseSeverity": "CRITICAL",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "LOW",
            "scope": "CHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H",
            "version": "3.1"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-22",
              "description": "CWE-22: Improper Limitation of a Pathname to a Restricted Directory (\u0027Path Traversal\u0027)",
              "lang": "en",
              "type": "CWE"
            },
            {
              "cweId": "CWE-23",
              "description": "CWE-23: Relative Path Traversal",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-24T09:08:04.188Z",
        "orgId": "cc1ad9ee-3454-478d-9317-d3e869d708bc",
        "shortName": "canonical"
      },
      "references": [
        {
          "tags": [
            "vdb-entry",
            "vendor-advisory"
          ],
          "url": "https://github.com/canonical/lxd/security/advisories/GHSA-q39m-8fx9-42fv"
        }
      ],
      "solutions": [
        {
          "lang": "en",
          "value": "Upgrade to LXD versions 4.0.13, 5.0.9, 5.21.7, 6.10 or later."
        }
      ],
      "source": {
        "discovery": "EXTERNAL"
      },
      "title": "Instance template path traversal allows arbitrary host file write as root"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "cc1ad9ee-3454-478d-9317-d3e869d708bc",
    "assignerShortName": "canonical",
    "cveId": "CVE-2026-66897",
    "datePublished": "2026-08-24T09:08:04.188Z",
    "dateReserved": "2026-07-28T07:41:26.310Z",
    "dateUpdated": "2026-08-25T03:55:49.930Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.