Bug 2521976

Summary: CVE-2026-48756 incus: Incus: Authenticated user can crash daemon via crafted backup tarball [fedora-all]
Product: [Fedora] Fedora Reporter: Laura Pardo <lpardo>
Component: incusAssignee: Neal Gompa <ngompa13>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: rawhideCC: dherrera, fabian, go-sig, jonathan, ngompa13, rcallicotte, reto.gantenbein
Target Milestone: ---Keywords: Security, SecurityTracking
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard: {"flaws": ["3b2da8cf-a746-45eb-b886-99ef50336bcf"]}
Fixed In Version: Doc Type: ---
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On:    
Bug Blocks: 2521005    

Description Laura Pardo 2026-08-24 14:35:36 UTC 
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.

Incus is a system container and virtual machine manager. Prior to version 7.1.0, `(*backend).CreateCustomVolumeFromBackup` in `internal/server/storage/backend.go` contains an unguarded `*time.Time` dereference on the `ExpiresAt` field of every volume-snapshot entry in an imported custom-volume backup. An authenticated user with `can_create_storage_volumes` permission on any project can crash the `incusd` daemon by uploading a backup tarball whose `volume_snapshots[*].expires_at` field is absent. This is a sibling-field variant of GHSA-r7w7-mmxr-47r9 (CVE-2026-40197). Commit `985a1dedf9f3e7ba729c93b654905ed510de25c2` added `if s == nil` at the top of the loop body, but did not guard the adjacent `*snapshot.ExpiresAt` deref 19 lines later. Every other consumer of `Config.VolumeSnapshots[i].ExpiresAt` in this same file already gates the deref with a nil-check — the asymmetric guard is the bug. Version 7.1.0 contains an updated patch.