Bug 2521012 (CVE-2026-48754)

Summary: CVE-2026-48754 github.com/lxc/incus/cmd/incusd: Incus: Denial of Service via malformed instance backup
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
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Priority: medium    
Version: unspecifiedKeywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in Incus, a system container and virtual machine manager. An authenticated user with `can_create_instances` permission can crash the `incusd` daemon by uploading a specially crafted instance backup tarball. This vulnerability, a nil-pointer dereference, leads to a Denial of Service (DoS) condition, making the system unavailable.
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Bug Depends On: 2521977    
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Description OSIDB Bzimport 2026-08-21 15:10:59 UTC
Incus is a system container and virtual machine manager. Prior to version 7.1.0, `(*backend).createDependentVolumesFromBackup` in `internal/server/storage/backend.go` contains a cluster of unguarded pointer derefs on every dependent-volume entry's `VolumeSnapshots[i]`, `Volume`, and `Pool` sub-fields. An authenticated user with `can_create_instances` permission on any project can crash the `incusd` daemon by uploading an instance backup tarball whose `dependent_volumes[*]` block contains a nil snapshot pointer (or omits `volume:` / `pool:`). This is a sibling-field variant of the 2026-05-04 batch fix `d768f81c0a1d985f35ae56219519822b080bf5e3` ("Properly check dependent volumes on import"). That commit added `if disk == nil` at the top of the outer loop, but did not guard the four sub-pointer fields the loop body dereferences naked. Version 7.1.0 contains an updated patch.