Cloudreve: SSRF guard bypass: checkIP does not decode IPv6-transition wrappers (NAT64, IPv4-compatible, 6to4) reaching internal and cloud-metadata addresses

{
  "id": "a989207df4f1e33c3e486c58b2f2d6929906cbef653999af27ad52d6b5909ff7",
  "url": "https://osv.dev/vulnerability/CVE-2026-79913",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Cloudreve: SSRF guard bypass: checkIP does not decode IPv6-transition wrappers (NAT64, IPv4-compatible, 6to4) reaching internal and cloud-metadata addresses",
    "summary": "Cloudreve is a self-hosted file management and sharing system. Prior to 4.18.0, the ValidateExternalURL server-side request forgery guard in pkg/request/ssrf.go passes resolved addresses to checkIP without decoding NAT64, IPv4-compatible, and 6to4 IPv4-in-IPv6 transition forms. An authenticated user with remote-download access can provide SrcUri through RemoteDownloadTask.createDownloadTask so a wrapper embedding a loopback, private, link-local, or cloud metadata IPv4 address is classified as public and fetched, exposing internal service responses and cloud instance credentials. IPv4-mapped IPv6 addresses remain blocked because Go converts that form with net.IP.To4. This issue is fixed in version 4.18.0.",
    "evidence": "osv:CVE-2026-79913",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2026-79913",
      "aliases": [
        "CVE-2026-79913",
        "GHSA-jvh5-97xg-v99f",
        "GO-2026-6572"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/cloudreve/cloudreve",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "0bb0ab833571d380153edd3529e01a7957b8b4ce"
                },
                {
                  "fixed": "1c5cad6dec7ec3037c6479e3a26a3909995d16a2"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "4.18.0"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "range": [
                      {
                        "fixed": "1c5cad6dec7ec3037c6479e3a26a3909995d16a2"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  },
                  {
                    "range": [
                      {
                        "fixed": "0bb0ab833571d380153edd3529e01a7957b8b4ce"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "4.18.0"
                  }
                ]
              }
            }
          ],
          "versions": [
            "4.17.0",
            "4.16.1",
            "4.16.0",
            "4.15.0",
            "4.14.1",
            "4.14.0",
            "4.13.0",
            "4.12.1",
            "4.12.0",
            "4.11.1",
            "4.11.0",
            "4.10.1",
            "4.10.0",
            "4.9.2",
            "4.9.1",
            "4.9.0",
            "4.8.0",
            "4.7.0",
            "4.6.0",
            "4.5.1",
            "4.5.0",
            "4.4.1",
            "4.4.0",
            "4.3.0",
            "4.2.0",
            "4.1.3",
            "4.1.2",
            "4.1.1",
            "4.1.0",
            "4.0.0",
            "4.0.0-beta.14",
            "4.0.0-beta.13",
            "4.0.0-beta.12",
            "4.0.0-beta.11",
            "4.0.0-beta.10",
            "4.0.0-beta.9",
            "4.0.0-beta.8",
            "4.0.0-beta.7",
            "4.0.0-beta.6",
            "3.8.3",
            "3.8.2",
            "3.8.1",
            "3.8.0",
            "3.8.0-beta1",
            "3.7.1",
            "3.7.0",
            "3.6.2",
            "3.6.1",
            "3.6.0",
            "3.6.0-beta1",
            "3.5.3",
            "3.5.2",
            "3.5.1",
            "3.5.0",
            "3.5.0-beta.3",
            "3.5.0-beta2",
            "3.5.0-beta1",
            "3.4.2",
            "3.4.1",
            "3.4.0",
            "3.4.0-beta1",
            "3.3.2",
            "3.3.1",
            "3.3.0",
            "3.2.1",
            "3.2.0",
            "3.1.1",
            "3.1.0",
            "3.0.0",
            "3.0.0-rc1",
            "3.0.0-beta3",
            "3.0.0-beta2",
            "3.0.0-beta1"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-79913.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:52.983425754Z",
      "provider": "osv",
      "references": [
        "https://github.com/cloudreve/cloudreve/releases/tag/4.18.0",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/79xxx/CVE-2026-79913.json",
        "https://github.com/cloudreve/cloudreve/security/advisories/GHSA-jvh5-97xg-v99f",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-79913",
        "https://github.com/cloudreve/cloudreve/commit/1c5cad6dec7ec3037c6479e3a26a3909995d16a2"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-697",
          "CWE-918"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/79xxx/CVE-2026-79913.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-79913",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 521678,
  "published_at": "2026-09-22T15:24:33.456+00:00"
}