Incus: CreateCustomVolumeFromBackup nil-pointer dereference on volume_snapshots[*].expires_at (sibling-field variant of GHSA-r7w7)

{
  "id": "778683acc85f9eace659c16bf781a19bfd6af9bd9d2ba63aa2ba8c3d4ed4c811",
  "url": "https://osv.dev/vulnerability/CVE-2026-48756",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Incus: CreateCustomVolumeFromBackup nil-pointer dereference on volume_snapshots[*].expires_at (sibling-field variant of GHSA-r7w7)",
    "summary": "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.",
    "evidence": "osv:CVE-2026-48756",
    "products": [],
    "severity": "low",
    "structured": {
      "id": "CVE-2026-48756",
      "aliases": [
        "CVE-2026-48756",
        "GHSA-xhqx-mgh3-3h7q",
        "GO-2026-5810"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/lxc/incus",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "42da2b16a4c8ed23f7b3bc50d7736d795f9a963a"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "7.1.0"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "7.1.0"
                      }
                    ],
                    "source": "DESCRIPTION"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v7.0.0",
            "v6.23.0",
            "v6.22.0",
            "v6.21.0",
            "v6.20.0",
            "v6.19.1",
            "v6.19.0",
            "v6.18.0",
            "v6.17.0",
            "v6.16.0",
            "v6.14.0",
            "v6.15.0",
            "v6.13.0",
            "v6.12.0",
            "v6.11.0",
            "v6.10.1",
            "v6.10.0",
            "v6.9.0",
            "v6.8.0",
            "v6.7.0",
            "v6.6.0",
            "v6.5.0",
            "v6.4.0",
            "v6.3.0",
            "v6.2.0",
            "v6.0.0",
            "v6.1.0",
            "v0.7.0",
            "v0.6.0",
            "v0.5.1",
            "v0.5.0",
            "v0.4.0",
            "v0.3.0",
            "v0.2.0",
            "v0.1.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-48756.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:27.278494505Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/48xxx/CVE-2026-48756.json",
        "https://github.com/lxc/incus/security/advisories/GHSA-xhqx-mgh3-3h7q",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-48756"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-476"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/48xxx/CVE-2026-48756.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-48756",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 493863,
  "published_at": "2026-08-21T14:10:34.151+00:00"
}