LXD has CreateCustomVolumeFromBackup nil-pointer dereference on volumes[0].snapshots[*].expires_at

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

6.5 · CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS

• CVE-2026-9639: 0.55% estimated exploitation activity in the next 30 days; percentile 46.25 (FIRST EPSS, 2026-11-10). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary (sibling-field variant of CVE-2026-40197 fix 05bc272) `(*lxdBackend).CreateCustomVolumeFromBackup` in `lxd/storage/backend_lxd.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 `EntitlementCanCreateStorageVolumes` permission on any project can crash the `lxd` daemon by uploading a backup tarball whose `volumes[0].snapshots[*].expires_at` field is omitted. This is a sibling-field variant of the CVE-2026-40197 fix (commit `05bc272`, "Validate snapshots from backup.yaml are non-nil", cherry-picked from incus commit `985a1dedf` / GHSA-r7w7-mmxr-47r9). That fix added `if snap == nil` guards at several consumer sites, but did not guard the adjacent `*snapshot.ExpiresAt` deref at line 8216. Every other consumer of this field in the same file already gates the deref with `if … != nil`…

Published by the source

6 Nov 2026, 19:37 UTC

Last modified by the source

6 Nov 2026, 19:45 UTC

Source last checked

7 Nov 2026, 06:05 UTC

1. Revision 2 · amended · 7 Nov 2026

   Amended from osv record GHSA-j93m-3j9p-m5m8

2. Revision 1 · created · 6 Nov 2026

   Published from ghsa record GHSA-j93m-3j9p-m5m8

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# Patch Next advisory brief: CVE-2026-9639

Advisory: LXD has CreateCustomVolumeFromBackup nil-pointer dereference on volumes[0].snapshots[*].expires_at
IDs: CVE-2026-9639, GHSA-j93m-3j9p-m5m8
Record: https://patchnext.com/advisories/cve-2026-9639 (revision 2, source checked 7 Nov 2026, 06:05 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/canonical/lxd 0.0.0-20260622081844-85f897013ccd. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/canonical/lxd: affected < 0.0.0-20260622081844-85f897013ccd; fixed in 0.0.0-20260622081844-85f897013ccd

## Suggested inspection (read-only)
- Go github.com/canonical/lxd: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/canonical/lxd.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-j93m-3j9p-m5m8 (GitHub-reviewed advisory GHSA-j93m-3j9p-m5m8 lists affected ranges: Go github.com/canonical/lxd >=0 <0.0.0-20260622081844-85f897013ccd)
- Verified: https://osv.dev/vulnerability/GHSA-j93m-3j9p-m5m8 (OSV record GHSA-j93m-3j9p-m5m8 lists affected ranges: Go github.com/canonical/lxd >=0 <0.0.0-20260622081844-85f897013ccd (fixed))

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