CVE-2026-40197: GO-2026-5612 - Incus has a Nil-Pointer Dereference via Custom Volume Import in github.com/lxc/incus

CVE-2026-40197 · Severity: medium · CVSS 6.5 · Published 2026-05-06

Incus 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 custom volume backup import subsystem contains a nil-pointer dereference vulnerability during import operations. In the snapshot import loop, the daemon iterates over entries from `srcBackup.Config.VolumeSnapshots` and assumes that each slice element is initialized, then dereferences fields such as `Name`, `Config`, `Description`, `CreatedAt`, and `ExpiresAt` without first validating the element itself. Because the yaml unmarshaler accepts explicit null array elements from an attacker-controlled index.yaml and converts them into nil pointers inside the slice, an attacker can supply a backup archive containing a null entry in the volume_snapshots array. This causes a nil-pointer dereference during custom volume import and terminates the daemon, resulting in denial of service on the affected node. 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.

Technologies: github.com/lxc/incus (Go), github.com/lxc/incus/v6 (Go), github.com/lxc/incus/v6/cmd/incusd (Go), github.com/lxc/incus/v7 (Go), Linuxcontainers Incus. Vendors: Go, Linuxcontainers.

Quick answers

Is CVE-2026-40197 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-40197 being exploited in the wild.
How severe is CVE-2026-40197?
Medium severity, with a CVSS score of 6.5, published 6 May 2026.
Which products and versions are affected?
github.com/lxc/incus (Go) SEMVER:introduced=0; github.com/lxc/incus/v6 (Go) SEMVER:introduced=0; github.com/lxc/incus/v6/cmd/incusd (Go) SEMVER:introduced=0,fixed=7.0.0; github.com/lxc/incus/v7 (Go) SEMVER:introduced=0,fixed=7.0.0.
Is there a fix for CVE-2026-40197?
Yes. github.com/lxc/incus/v6/cmd/incusd (Go): upgrade to 7.0.0 or later; github.com/lxc/incus/v7 (Go): upgrade to 7.0.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
Am I affected by CVE-2026-40197?
Check whether you run github.com/lxc/incus (Go), github.com/lxc/incus/v6 (Go), github.com/lxc/incus/v6/cmd/incusd (Go) or one of the others listed at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • github.com/lxc/incus/v6/cmd/incusd (Go): upgrade to 7.0.0 or later
    go get github.com/lxc/incus/v6/cmd/incusd@v7.0.0
  • github.com/lxc/incus/v7 (Go): upgrade to 7.0.0 or later
    go get github.com/lxc/incus/v7@v7.0.0

Affected products

  • github.com/lxc/incus (Go) SEMVER:introduced=0
  • github.com/lxc/incus/v6 (Go) SEMVER:introduced=0
  • github.com/lxc/incus/v6/cmd/incusd (Go) SEMVER:introduced=0,fixed=7.0.0
  • github.com/lxc/incus/v7 (Go) SEMVER:introduced=0,fixed=7.0.0
  • Linuxcontainers Incus

Identifiers

  • CVE-2026-40197
  • GHSA-r7w7-mmxr-47r9
  • GO-2026-5612

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