{"api_version":"1","generated_at":"2026-09-29T04:32:43+00:00","cve":"CVE-2026-66897","urls":{"html":"https://cve.report/CVE-2026-66897","api":"https://cve.report/api/cve/CVE-2026-66897.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-66897","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-66897"},"summary":{"title":"Instance template path traversal allows arbitrary host file write as root","description":"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.","state":"PUBLISHED","assigner":"canonical","published_at":"2026-08-24 10:16:39","updated_at":"2026-09-11 15:28:53"},"problem_types":["CWE-22","CWE-23","CWE-22 CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')","CWE-23 CWE-23: Relative Path Traversal"],"metrics":[{"version":"3.1","source":"security@ubuntu.com","type":"Secondary","score":"9.9","severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H","baseScore":9.9,"baseSeverity":"CRITICAL","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"CHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"}},{"version":"3.1","source":"CNA","type":"CVSS","score":"9.9","severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H","data":{"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"}}],"references":[{"url":"https://github.com/canonical/lxd/security/advisories/GHSA-q39m-8fx9-42fv","name":"https://github.com/canonical/lxd/security/advisories/GHSA-q39m-8fx9-42fv","refsource":"security@ubuntu.com","tags":["Vendor Advisory","Exploit"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-66897","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-66897","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Canonical","product":"LXD","version":"affected 4.0.0 4.0.13 semver","platforms":["Linux"]},{"source":"CNA","vendor":"Canonical","product":"LXD","version":"affected 5.0.0 5.0.9 semver","platforms":["Linux"]},{"source":"CNA","vendor":"Canonical","product":"LXD","version":"affected 5.21.0 5.21.7 semver","platforms":["Linux"]},{"source":"CNA","vendor":"Canonical","product":"LXD","version":"affected 6.0 6.10 semver","platforms":["Linux"]}],"timeline":[],"solutions":[{"source":"CNA","title":"","value":"Upgrade to LXD versions 4.0.13, 5.0.9, 5.21.7, 6.10 or later.","time":"","lang":"en"}],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[{"cve_year":"2026","cve_id":"66897","vulnerable":"1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"a","cpe4":"canonical","cpe5":"lxd","cpe6":"*","cpe7":"*","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"*"}],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"66897","cve":"CVE-2026-66897","epss":"0.006190000","percentile":"0.472030000","score_date":"2026-08-30","updated_at":"2026-08-31 00:14:06"},"legacy_qids":[]},"source_records":{"cve_program":{"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'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."}],"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 ('Path Traversal')","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"},"nvd":{"publishedDate":"2026-08-24 10:16:39","lastModifiedDate":"2026-09-11 15:28:53","problem_types":["CWE-22","CWE-23","CWE-22 CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')","CWE-23 CWE-23: Relative Path Traversal"],"metrics":{"cvssMetricV31":[{"source":"security@ubuntu.com","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H","baseScore":9.9,"baseSeverity":"CRITICAL","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"CHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"},"exploitabilityScore":3.1,"impactScore":6}],"ssvcV203":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","ssvcData":{"timestamp":"2026-08-24T00:00:00+00:00","id":"CVE-2026-66897","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalImpact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}]},"configurations":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:canonical:lxd:*:*:*:*:*:*:*:*","versionEndExcluding":"4.0.13","matchCriteriaId":"C0F22A55-5146-4B91-9D3E-BC4509F506BE"},{"vulnerable":true,"criteria":"cpe:2.3:a:canonical:lxd:*:*:*:*:*:*:*:*","versionStartIncluding":"5.0.0","versionEndExcluding":"5.0.9","matchCriteriaId":"5DE002EB-DEFA-4284-A2C5-F68C71B121DF"},{"vulnerable":true,"criteria":"cpe:2.3:a:canonical:lxd:*:*:*:*:*:*:*:*","versionStartIncluding":"5.1","versionEndExcluding":"5.21.7","matchCriteriaId":"84E5D160-5D14-4E78-AEDD-E9906420FB2E"},{"vulnerable":true,"criteria":"cpe:2.3:a:canonical:lxd:*:*:*:*:*:*:*:*","versionStartIncluding":"6.0","versionEndIncluding":"6.9","matchCriteriaId":"372FD242-9957-420D-BDDC-D4C81BB996D4"}]}]}]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"66897","Ordinal":"1","Title":"Instance template path traversal allows arbitrary host file writ","CVE":"CVE-2026-66897","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"66897","Ordinal":"1","NoteData":"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.","Type":"Description","Title":"Instance template path traversal allows arbitrary host file writ"}]}}}