CVE-2026-40251

NameCVE-2026-40251
DescriptionIncus is a system container and virtual machine manager. In versions before 7.0.0, missing validation logic in the storage volume import logic allows an authenticated user with access to the storage volume feature to cause the Incus daemon to crash. The backup restore subsystem contains an out-of-bounds panic vulnerability caused by an invalid bounds check when indexing snapshot metadata arrays, and the same flawed pattern also appears in the migration path. When iterating through physical snapshots provided in a backup archive, the loop uses the index to look up corresponding metadata in the parsed `Config.Snapshots` and `Config.VolumeSnapshots` slices. The guard condition `len(slice) >= i-1` is incorrect because it can still evaluate to true when the subsequent slice[i] access is out of bounds. An attacker can submit a backup archive that contains physical snapshot directories while supplying a tampered `index.yaml` with an empty or truncated snapshot metadata array, causing the daemon to index beyond the end of the metadata slice and crash. Repeated use of this issue can be used to keep Incus offline, causing a denial of service. This issue is fixed in version 7.0.0.
SourceCVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
ReferencesDSA-6244-1, DSA-6247-1
Debian Bugs1135644

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
incus (PTS)trixie (security), trixie6.0.4-2+deb13u7fixed
forky, sid7.0.0-1fixed
lxd (PTS)bookworm, bookworm (security)5.0.2-5+deb12u6fixed
trixie (security), trixie5.0.2+git20231211.1364ae4-9+deb13u6fixed

The information below is based on the following data on fixed versions.

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
incussourcetrixie6.0.4-2+deb13u7DSA-6244-1
incussource(unstable)7.0.0-11135644
lxdsourcebookworm5.0.2-5+deb12u6DSA-6247-1
lxdsourcetrixie5.0.2+git20231211.1364ae4-9+deb13u6DSA-6247-1
lxdsource(unstable)(unfixed)

Notes

https://github.com/lxc/incus/security/advisories/GHSA-4m88-wxj4-9qj6
https://github.com/lxc/incus/pull/3273

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