Vulnerability details

CVE-2026-40251

lxc incus

Incus out-of-bounds panic in snapshot metadata handling allows denial of service

CVSS 4.0
7.1High

Official 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 scores

ScoreVersionSourceVector
7.1High 4.0 CVEProject cvelistV5 (CNA) (GitHub_M) 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

Affected products

VendorProductVersionsSource
lxc incus < 7.0.0 CVEProject cvelistV5 (CNA)

References and advisories

2
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Details

Published
2026-05-07
Last updated
2026-05-07
State
Published
Assigner (CNA)
GitHub_M

Exploit prediction (EPSS)

0.4%
Probability of exploitation in 30 days
35.3%
Percentile (among all CVEs)

SSVC assessment (CISA)

Automatable
Yes
Exploitation
Proof of concept
Technical impact
Partial

Weaknesses (CWE)

  • CWE-129
    Improper Validation of Array Index