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Vulnerability · Published May 7, 2026 · Assigned by GitHub_M

CVE-2026-41684Incus: Nil Dereferences on Restore via Malformed YAML

Medium 6.5

In plain English

A medium-severity null pointer dereference in incus from lxc. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 35% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)6.5Medium
Exploit odds (30 days)0.4%top 64.7% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Alpine:v3.24incus7.0.0-r0ALPINE-CVE-2026-41684
Debian:13incus6.0.4-2+deb13u7DEBIAN-CVE-2026-41684
Debian:14incus7.0.0-1DEBIAN-CVE-2026-41684
Debian:12lxdno fix listedDEBIAN-CVE-2026-41684
Debian:13lxd5.0.2+git20231211.1364ae4-9+deb13u6DEBIAN-CVE-2026-41684
Gogithub.com/lxc/incusno fix listedGO-2026-5742
Gogithub.com/lxc/incus/v6no fix listedGO-2026-5742
Gogithub.com/lxc/incus/v6/cmd/incusdno fix listedGHSA-x5r6-jr56-89pv
Ubuntu:25.10incusno fix listedUBUNTU-CVE-2026-41684
Ubuntu:26.10incusno fix listedUBUNTU-CVE-2026-41684

Affected products (as reported)

VendorProductVersions
lxc incus < 7.0.0

Weakness: CWE-476 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

References