🛡️ CVE-2026-40251 on Debian — incus

⚪ Unknown ✅ No Known Exploit OSV
N/A
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

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 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.

Distribution advisory

This page covers CVE-2026-40251 as tracked by Debian, for the package incus. The fix is available in version 7.0.0-1; earlier versions remain affected.

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is low, an attacker needs low-level privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality none, integrity none, availability high.

Affected software

DEBIAN-CVE-2026-40251 is recorded against 2 packages.

  • incus (fixed in 7.0.0-1)
  • lxd (fixed in 5.0.2+git20231211.1364ae4-9+deb13u6)

Timeline and source

Published on 6 May 2026 and last revised on 4 August 2026. No public exploit is currently recorded for this entry. Record sourced from OSV.

References

security-tracker.debian.org (Advisory)

CVE-2026-40251 on other distributions

Each distribution ships its own build and its own fixed version. Pick the one you run:

Details

Severity Unknown
CVSS Score N/A
CVSS Vector CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CWE N/A
Public Exploit ✅ No
Source OSV
Published 2026-05-06
Updated 2026-08-12
Modified 2026-08-04
Fix URL N/A

Affected Packages

Software From version Fixed in
incus 7.0.0-1
lxd 5.0.2+git20231211.1364ae4-9+deb13u6

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