Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain
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AccessObtain low-privilege LXD import access
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DeliveryCraft archive with symlinked backup.yaml
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ExploitSubmit archive for image/backup import
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ExecutionLXD follows symlink, reads unconfined config
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ImpactExecute arbitrary commands as root on host
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A01:2025 - Broken Access Control
ASVS 5.0
V5 - File Handling Symlink resolution safety
|
| Exploitation Conditions | Requires that LXD import or unpack an attacker-supplied image or backup archive that contains a backup.yaml entry crafted as a symbolic link - that malicious-symlink-in-archive is the concrete trigger. Exploitation therefore depends on the attacker being able to initiate an import/restore (typically authenticated low-privilege LXD access, PR:L) or on an operator being induced to import the crafted archive; it is not a passive network exploit against an idle daemon. Limiting factors: deployments that never import externally-sourced images/backups, or that restrict import to fully trusted administrators, are not realistically reachable, and the flaw is specific to LXD's archive-unpack path rather than default idle operation. |
| Impact | The signals are largely consistent and point to a genuine high priority: CVSS 9.9 with AV:N/AC:L/PR:L/UI:N and a scope change (S:C) reflecting container-to-host escape, reported by Canonical's own security team through an official GitHub advisory, which lends high credibility to the technical claim. The main caveat is that AV:N is optimistic for the described workflow - exploitation hinges on getting a crafted archive imported, which in practice requires at least authenticated/low-privileged LXD API access (PR:L) or convincing an operator to import the archive, so realistic reachability is narrower than a pure remote-unauthenticated bug. EPSS is not provided and there is no KEV listing or known POC, so exploitation probability cannot be quantified from the data, and the 'Information Disclosure' tag appears mislabeled given the description clearly states root command execution. Given the trivial exploit primitive (a symlink in an archive) and root-level impact, any organization running LXD as a multi-tenant or shared host - even a mid-sized municipal IT team in legnica should treat this as urgent - ought to prioritize patching over waiting for exploit code to surface. |
| Exploit ScenarioDerived | An attacker with low-privileged access to an LXD deployment (or one who can get an operator to restore a supplied backup) crafts a backup archive in which backup.yaml is a symbolic link pointing outside the extraction directory. When LXD imports/unpacks the archive, it follows the symlink and processes attacker-controlled configuration metadata as root, resulting in arbitrary command execution on the host. No public POC is currently identified, but the primitive (a symlink inside a tar archive) is simple to construct. |
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Alert meAnalysisAIv1 – Aug 12, 2026
Privilege escalation to host root in Canonical LXD occurs when the container manager unpacks crafted image or backup archives, because it follows a symbolic link where the backup.yaml metadata file should be and then processes attacker-controlled configuration outside its intended confinement. A low-privileged LXD user who can import a malicious archive can execute arbitrary commands as root on the underlying host, breaking the container/host trust boundary (scope change). Rated CVSS 9.9; no public exploit identified at time of analysis and not listed in CISA KEV, but the fix is coordinated through GitHub advisory GHSA-fv82-v4fj-mm4m.
RemediationAI
Patch available per vendor advisory: upgrade LXD to the fixed release identified in GHSA-fv82-v4fj-mm4m (https://github.com/canonical/lxd/security/advisories/GHSA-fv82-v4fj-mm4m); the exact patched version is published there and should be applied on all hosts running the LXD daemon. Until patched, restrict who can import images and backups - treat lxc image import / lxc import (backup restore) as a privileged operation and do not accept archives from untrusted tenants or third parties, since the vulnerability triggers during unpack. As compensating controls, limit LXD API access to trusted administrators (tighten TLS client-cert trust and any restricted/project-scoped user permissions that allow import), and validate/quarantine external archives out-of-band before import; the trade-off is reduced self-service for tenants and added operational overhead. Avoid importing backups produced on untrusted hosts.
Affected VersionsENISA
Affected Packages
Source: OSV (Open Source Vulnerabilities)
Affects your stack
Affects 1 package in euvd
Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
LXD is a system-container and VM manager (built on LXC/liblxc) that ships images and instance backups as archives containing a backup.yaml file describing the instance configuration and metadata. This flaw is CWE-59 (Link Following / improper link resolution): during import/unpack LXD does not verify that backup.yaml is a regular file confined within the extraction directory, so a symlink placed at that path is dereferenced and its target is read and acted upon as trusted configuration. Because the daemon runs as root on the host, processing this unconfined metadata leads to command execution with root privileges - a classic archive-extraction symlink traversal that escapes the container boundary into the host.
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Severity by source
AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Import is normally an authenticated low-privilege API action (PR:L) over the network (AV:N); the symlink primitive is trivial (AC:L) and container-to-host root breaks scope (S:C) with full C/I/A loss.
Primary rating from Vendor (ubuntu).
CVSS VectorVendor: ubuntu
Lifecycle Timeline
2DescriptionCVE.org
A link following vulnerability in LXD allows an attacker to achieve root command execution on the host system. During the import or unpacking of crafted image or backup archives, LXD fails to properly validate and confine the backup.yaml file when it exists as a symbolic link. An attacker can exploit this flaw by providing a malicious archive with a symlinked backup.yaml file, causing LXD to process unconfined configuration metadata and execute arbitrary commands with root privileges.
Executive ViewAI
A critical privilege escalation in Canonical LXD enables low-privileged users with archive import permissions to reach host root access, breaking the fundamental isolation between container management and underlying infrastructure. With no vendor patch available, organizations relying on LXD cannot depend on rapid remediation and must immediately restrict who can manage archives and backups. Every LXD deployment represents a direct attack surface where user actions can compromise the entire host system.
No vendor-released patch identified at time of analysis. Interim mitigations: restrict archive and backup import functionality to trusted administrators only using filesystem and access control mechanisms; isolate LXD hosts on dedicated network segments if available; implement comprehensive audit logging for all archive import operations; consider temporary disabling of LXD on non-critical systems. Continuously monitor GHSA-fv82-v4fj-mm4m for patch availability and release timeline.
Threat Intelligence Overview
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
Information disclosure occurs when an application unintentionally exposes sensitive data that aids attackers in reconnaissance or directly compromises security.
Cross-site request forgery in the LXD-UI component of Canonical LXD 5.0 before 5.0.5, 5.1 before 5.21.4, and 6.0 before
Privilege escalation in Canonical LXD's operations API (LXD before 6.5 and LXD 5.21 before 5.21.4) allows an authenticat
Authenticated remote attackers with access to the Canonical LXD instance log retrieval or deletion endpoints can read ar
Server-side template injection in Canonical LXD's instance snapshot naming feature lets an authenticated user who can mo
Unauthenticated project enumeration in Canonical LXD 5.21.x before 5.21.4 and 6.x before 6.5 lets remote attackers deter
Unauthenticated remote attackers can confirm the existence of LXD projects on Canonical LXD by comparing HTTP status cod
Host root code execution in Canonical LXD arises from a path-traversal flaw in instance template processing, letting an
Improper certificate validation in the HTTPS API listener of Canonical LXD lets an unauthenticated remote attacker prese
Arbitrary host file read and write in Canonical LXD occurs because the image import/unpack routine does not verify wheth
Canonical LXD's NVIDIA GPU passthrough configuration handler fails to sanitize newline characters in user-supplied `nvid
Path traversal in Canonical's LXD container and VM manager allows a user with backup import/restore privileges to write
Authorization bypass in Canonical LXD (6.0 before 6.10, 5.21.x before 5.21.6, 5.0.x before 5.0.8) lets an authenticated
EUVD-2026-57538
NVD
CVE.org
EPSS
Vulnrichment
GitHub
VulDB
Exploit-DB