Incus Vulnerable to Panic via Snapshot Bounds Check

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

7.1 · CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N · score source

EPSS

• CVE-2026-40251: 0.41% estimated exploitation activity in the next 30 days; percentile 35.14 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary Missing validation logic in the storage volume import logic allows an authenticated user with access to Incus' storage volume feature to cause the Incus daemon to crash. Repeated use of this issue can be used to keep Incus offline causing a denial of service. Details The backup restore subsystem contains an out-of-bounds panic vulnerability caused by an invalid bounds check when indexing snapshot metadata arrays. 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 i to look up corresponding metadata in the parsed Config.Snapshots and Config.VolumeSnapshots slices. To ensure that the metadata slice is long enough, the code uses the guard condition len(slice) = i-1. This check is incorrect because it can still evaluate to true when the subsequent slice[i] access is out of bounds, including when i = len(slice), triggering a runtime panic. An attacker can trigger this by…

Published by the source

4 May 2026, 19:16 UTC

Last modified by the source

8 May 2026, 19:26 UTC

Source last checked

26 Oct 2026, 15:20 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-4m88-wxj4-9qj6

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# Patch Next advisory brief: CVE-2026-40251

Advisory: Incus Vulnerable to Panic via Snapshot Bounds Check
IDs: CVE-2026-40251, GHSA-4m88-wxj4-9qj6
Record: https://patchnext.com/advisories/cve-2026-40251 (revision 1, source checked 26 Oct 2026, 15:20 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.1)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/lxc/incus/v6/cmd/incusd 7.0.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/lxc/incus/v6/cmd/incusd: affected < 7.0.0; fixed in 7.0.0

## Suggested inspection (read-only)
- Go github.com/lxc/incus/v6/cmd/incusd: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/lxc/incus/v6/cmd/incusd.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-4m88-wxj4-9qj6 (GitHub-reviewed advisory GHSA-4m88-wxj4-9qj6 lists affected ranges: Go github.com/lxc/incus/v6/cmd/incusd >=0 <7.0.0)

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