CVE-2026-9639

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.

A path traversal vulnerability in LXD allows an attacker to manipulate file system paths during backup import and restore operations. When importing or restoring a backup archive, LXD fails to validate instance and storage volume names contained within the archive metadata. An attacker can exploit this flaw by supplying a crafted backup archive with malicious instance or volume names containing path traversal sequences, potentially allowing file access or overwriting outside the designated restore directory.

An improper validation vulnerability in the instancePostMigration function in lxd/instance_post.go of LXD allows an authenticated attacker with can_create_instances permissions on a restricted project to bypass project-level security restrictions. When migrating an instance between projects, LXD fails to validate the instance's configuration against the target project's enforced restrictions.

An authorization bypass vulnerability in LXD allows an authenticated user to bypass project-level disk and volume limits. Two related code paths fail to verify resource limits during volume operations: the storagePoolVolumeTypePostMove function omits the limits.AllowVolumeCreation check before moving a volume across projects, and volume snapshot restore operations skip the AllowVolumeUpdate check when the configuration is nil.

An improper neutralization of special elements vulnerability in LXD's NVIDIA instance configuration handling allows an authenticated attacker to inject arbitrary configuration directives. By supplying newline characters within the 'nvidia.driver.capabilities' or 'nvidia.require.*' configuration values, an attacker can manipulate the generated lxc.conf file.

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. LXD performs restriction checks before configuration merging is complete, creating a time-of-check to time-of-use (TOCTOU) condition.

An authorization bypass vulnerability in LXD allows an authenticated attacker to bypass target project restrictions during instance migration. When migrating an instance to a target project, LXD accepts configuration overrides without validating the new configuration against the target project's enforced restrictions.

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.

A link following vulnerability in LXD allows an attacker to achieve arbitrary file read and write operations on the host system. When importing or unpacking an image archive, LXD fails to validate whether the metadata.yaml file is a symbolic link. An attacker can exploit this flaw by providing a crafted image archive with a symlinked metadata.yaml file pointing to target file paths on the host system.

An authorization bypass vulnerability in LXD allows an authenticated attacker to bypass target project security restrictions during cross-project instance migrations. When moving an instance cross-project to a different cluster member via POST /1.0/instances/{name} with migration: true, project: <target>, and target: <member>, the destination node skips all project restriction checks because the request arrives as an internal cluster notification. An attacker can exploit this to introduce disallowed instance configurations into a restricted project.