CVE-2026-41684: medium-severity vulnerability in lxc incus
Incus: Nil Dereferences on Restore via Malformed YAML
Published
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13Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 6.5epss 0.4%
Incus is a system container and virtual machine manager. Prior to version 7.0.0, backup.GetInfo() trusts the inline backup/index.yaml config when present and only falls back to parsing the legacy backup/container/backup.yaml file if result.Config == nil. As a result, an archive can carry a valid inline config that passes the initial import preflight while also carrying a malformed legacy backup/container/backup.yaml file that is reparsed later from the restored file system. ParseConfigYamlFile() accepts YAML documents with no container section, and multiple downstream consumers then dereference. Container without checking for nil. Confirmed examples in the instance restore and import flow include backup.UpdateInstanceConfig() and internalImportFromBackup(). An authenticated user with permission to import instance backups may be able to crash the Incus daemon with a crafted backup archive whose inline backup/index.yaml is valid but whose extracted legacy backup.yaml omits container. The crash occurs in the restore path after archive extraction has begun. This issue has been patched in version 7.0.0.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Affected products
lxc · incusRelated CVEs — lxc incus
In the same product, most dangerous first.
CVE-2026-48769CRITICALIncus has an arbitrary file write on its client due to trusted image hashEPSS 0.8%CVE-2026-48755CRITICALIncus has an argument injection in backup compression algorithm leading to AFW and ACEEPSS 0.8%CVE-2026-48752CRITICALIncus has arbitrary file read+write on host via templates/ symlink in malicious imageEPSS 0.8%CVE-2026-48750CRITICALIncus has an arbitrary file write on host via `exec-output` symlink in crafted imageEPSS 0.8%CVE-2026-48749CRITICALIncus has an arbitrary file read+write on host via rootfs/ symlink in malicious imageEPSS 0.8%CVE-2026-23954HIGHIncus container image templating arbitrary host file read and writeEPSS 0.8%