Unauthenticated Miniflux user can bypass allowed networks check to obtain Prometheus metrics

{
  "id": "07d4ff853be49d025ab6fe9ff5b881160910cf3946ef038c2e1c87cd08c3dfa8",
  "url": "https://osv.dev/vulnerability/CVE-2023-27591",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Unauthenticated Miniflux user can bypass allowed networks check to obtain Prometheus metrics",
    "summary": "Miniflux is a feed reader. Prior to version 2.0.43, an unauthenticated user can retrieve Prometheus metrics from a publicly reachable Miniflux instance where the `METRICS_COLLECTOR` configuration option is enabled and `METRICS_ALLOWED_NETWORKS` is set to `127.0.0.1/8` (the default). A patch is available in Miniflux 2.0.43. As a workaround, set `METRICS_COLLECTOR` to `false` (default) or run Miniflux behind a trusted reverse-proxy.",
    "evidence": "osv:CVE-2023-27591",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2023-27591",
      "aliases": [
        "CVE-2023-27591",
        "GHSA-3qjf-qh38-x73v"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/miniflux/v2",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "ab209df78f41cfd2e3b273682e29c492351575d1"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "2.0.43"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "range": [
                      {
                        "fixed": "ab209df78f41cfd2e3b273682e29c492351575d1"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "2.0.43"
                  },
                  {
                    "cpe": "cpe:2.3:a:miniflux_project:miniflux:*:*:*:*:*:go:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "2.0.43"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "versions": [
            "2.0.42",
            "2.0.41",
            "2.0.40",
            "2.0.39",
            "2.0.38",
            "2.0.37",
            "2.0.36",
            "2.0.35",
            "2.0.34",
            "2.0.33",
            "2.0.32",
            "2.0.31",
            "2.0.30",
            "2.0.29",
            "2.0.28",
            "2.0.27",
            "2.0.26",
            "2.0.25",
            "2.0.24",
            "2.0.23",
            "2.0.22",
            "2.0.21",
            "2.0.20",
            "2.0.19",
            "2.0.18",
            "2.0.17",
            "2.0.16",
            "2.0.15",
            "2.0.14",
            "2.0.13",
            "2.0.12",
            "2.0.11",
            "2.0.10",
            "2.0.9",
            "2.0.8",
            "2.0.7",
            "2.0.6",
            "2.0.5",
            "2.0.4",
            "2.0.3",
            "2.0.2",
            "2.0.1",
            "2.0.0",
            "2.0.0-rc1"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2023-27591.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:28.010203221Z",
      "provider": "osv",
      "references": [
        "https://github.com/miniflux/v2/releases/tag/2.0.43",
        "https://miniflux.app/docs/configuration.html#metrics-collector",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/27xxx/CVE-2023-27591.json",
        "https://github.com/miniflux/v2/security/advisories/GHSA-3qjf-qh38-x73v",
        "https://nvd.nist.gov/vuln/detail/CVE-2023-27591",
        "https://github.com/miniflux/v2/pull/1745"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-1220",
          "CWE-200"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/27xxx/CVE-2023-27591.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2023-27591",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 494860,
  "published_at": "2023-03-17T19:04:03.702+00:00"
}