CVE-2026-40251: CWE-129: Improper Validation of Array Index in lxc incus
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.
AI Analysis
Technical Summary
Incus, a system container and virtual machine manager, has a vulnerability (CWE-129) in versions before 7.0.0 where the storage volume import logic lacks proper validation of array indices. The backup restore subsystem incorrectly checks bounds when indexing snapshot metadata arrays, allowing an authenticated user to cause an out-of-bounds panic by submitting a backup archive with manipulated snapshot metadata. This leads to daemon crashes and potential denial of service. The vulnerability is addressed in version 7.0.0.
Potential Impact
An authenticated user with access to the storage volume feature can cause the Incus daemon to crash by exploiting improper array index validation during backup restore operations. This results in a denial of service condition, potentially disrupting container and virtual machine management until the daemon is restarted or patched.
Mitigation Recommendations
This vulnerability is fixed in Incus version 7.0.0. Users should upgrade to version 7.0.0 or later to remediate this issue. No official patch or temporary fix is indicated beyond upgrading. Since this is not a cloud service, remediation requires user action to update the software.
CVE-2026-40251: CWE-129: Improper Validation of Array Index in lxc incus
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.
CVSS v4.0
Score 7.1high
Affected software
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
Incus, a system container and virtual machine manager, has a vulnerability (CWE-129) in versions before 7.0.0 where the storage volume import logic lacks proper validation of array indices. The backup restore subsystem incorrectly checks bounds when indexing snapshot metadata arrays, allowing an authenticated user to cause an out-of-bounds panic by submitting a backup archive with manipulated snapshot metadata. This leads to daemon crashes and potential denial of service. The vulnerability is addressed in version 7.0.0.
Potential Impact
An authenticated user with access to the storage volume feature can cause the Incus daemon to crash by exploiting improper array index validation during backup restore operations. This results in a denial of service condition, potentially disrupting container and virtual machine management until the daemon is restarted or patched.
Mitigation Recommendations
This vulnerability is fixed in Incus version 7.0.0. Users should upgrade to version 7.0.0 or later to remediate this issue. No official patch or temporary fix is indicated beyond upgrading. Since this is not a cloud service, remediation requires user action to update the software.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-04-10T17:31:45.786Z
- Cvss Version
- 4.0
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 69fba9cccbff5d86105e9c3c
Added to database: 05/06/2026, 20:51:24 UTC
Last enriched: 05/14/2026, 03:49:29 UTC
Last updated: 07/31/2026, 19:22:58 UTC
Views: 100
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