CVE-2026-85526

Path traversal in the Btrfs storage driver (unpackVolume) in Canonical LXD on Linux allows an authenticated user with instance creation privileges to delete or replace arbitrary files and directories on the host filesystem as root via a crafted subvolumes[].path entry in backup/optimized_header.yaml during a btrfs optimized backup import.

CVSS v3 9.9 CRITICAL

9.9^/10

CVSS v3 : CRITICAL

Vector :

Exploitability : 3.1 / Impact : 6.0

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope CHANGED

References

Link	Resource
https://github.com/canonical/lxd-private/pull/103
https://github.com/canonical/lxd-private/pull/104
https://github.com/canonical/lxd-private/pull/105
https://github.com/canonical/lxd-private/pull/84
https://github.com/canonical/lxd-private/pull/87
https://github.com/canonical/lxd/security/advisories/GHSA-h85r-gjgx-g2rv

Configurations

No configuration.

History

28 Sep 2026, 14:17

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-09-28 14:17

Updated : 2026-09-29 04:18

NVD link : CVE-2026-85526

Mitre link : CVE-2026-85526

CVE.ORG link : CVE-2026-85526

JSON object : View

Products Affected

No product.

CWE

CWE-22

Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

{"id": "CVE-2026-85526", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-85526", "role": "CISA Coordinator", "options": [{"exploitation": "poc"}, {"automatable": "no"}, {"technicalImpact": "total"}], "version": "2.0.3", "timestamp": "2026-09-28T00:00:00+00:00"}}], "cvssMetricV31": [{"type": "Secondary", "source": "security@ubuntu.com", "cvssData": {"scope": "CHANGED", "version": "3.1", "baseScore": 9.9, "attackVector": "NETWORK", "baseSeverity": "CRITICAL", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "HIGH"}, "impactScore": 6.0, "exploitabilityScore": 3.1}]}, "affected": [{"source": "security@ubuntu.com", "affectedData": [{"repo": "https://github.com/canonical/lxd", "vendor": "Canonical", "product": "LXD", "versions": [{"status": "affected", "version": "4.0.0", "lessThan": "4.0.14", "versionType": "semver"}, {"status": "affected", "version": "5.0.0", "lessThan": "5.0.10", "versionType": "semver"}, {"status": "affected", "version": "5.21.0", "lessThan": "5.21.8", "versionType": "semver"}, {"status": "affected", "version": "6.0", "lessThan": "6.10", "versionType": "semver"}], "platforms": ["Linux"], "packageName": "LXD", "defaultStatus": "unaffected"}]}], "published": "2026-09-28T14:17:20.423", "references": [{"url": "https://github.com/canonical/lxd-private/pull/103", "source": "security@ubuntu.com"}, {"url": "https://github.com/canonical/lxd-private/pull/104", "source": "security@ubuntu.com"}, {"url": "https://github.com/canonical/lxd-private/pull/105", "source": "security@ubuntu.com"}, {"url": "https://github.com/canonical/lxd-private/pull/84", "source": "security@ubuntu.com"}, {"url": "https://github.com/canonical/lxd-private/pull/87", "source": "security@ubuntu.com"}, {"url": "https://github.com/canonical/lxd/security/advisories/GHSA-h85r-gjgx-g2rv", "source": "security@ubuntu.com"}], "vulnStatus": "Deferred", "weaknesses": [{"type": "Secondary", "source": "security@ubuntu.com", "description": [{"lang": "en", "value": "CWE-22"}]}], "descriptions": [{"lang": "en", "value": "Path traversal in the Btrfs storage driver (unpackVolume) in Canonical LXD on Linux allows an authenticated user with instance creation privileges to delete or replace arbitrary files and directories on the host filesystem as root via a crafted subvolumes[].path entry in backup/optimized_header.yaml during a btrfs optimized backup import."}], "lastModified": "2026-09-29T04:18:00.690", "sourceIdentifier": "security@ubuntu.com"}