Ghost before 6.20.0 File Read via URL Encoding Bypass

{
  "id": "24e9374310c77ee7e4d353f18f5fe0453560b71ed05ac6ee1deb97e9dff1b8ed",
  "url": "https://osv.dev/vulnerability/BIT-ghost-2026-103276",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Ghost before 6.20.0 File Read via URL Encoding Bypass",
    "summary": "Ghost versions before 6.20.0 contain a file extension filtering bypass vulnerability that allows unauthenticated attackers to read theme templates and metadata. Attackers can use URL encoding to bypass extension validation and access sensitive theme files.",
    "evidence": "osv:BIT-ghost-2026-103276",
    "products": [
      {
        "name": {
          "value": "ghost",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.20.0",
            "evidence": "/affected/0/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "medium",
    "structured": {
      "id": "BIT-ghost-2026-103276",
      "aliases": [
        "BIT-ghost-2026-103276",
        "CVE-2026-103276",
        "GHSA-6v8p-3jx9-8chr"
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "SEMVER",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "6.20.0"
                }
              ]
            }
          ],
          "package": {
            "name": "ghost",
            "purl": "pkg:bitnami/ghost",
            "ecosystem": "Bitnami"
          },
          "severity": [
            {
              "type": "CVSS_V4",
              "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X"
            }
          ],
          "database_specific": {
            "source": "https://github.com/bitnami/vulndb/tree/main/data/ghost/BIT-ghost-2026-103276.json"
          }
        }
      ],
      "modified": "2026-10-09T12:10:40.519596358Z",
      "provider": "osv",
      "references": [
        "https://github.com/TryGhost/Ghost/security/advisories/GHSA-6v8p-3jx9-8chr",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-103276",
        "https://www.vulncheck.com/advisories/ghost-before-6.20.0-file-read-via-url-encoding-bypass"
      ],
      "provider_metadata": {
        "cpes": [
          "cpe:2.3:a:ghost:ghost:*:*:*:*:*:node.js:*:*"
        ],
        "severity": "Medium"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-103276",
        "evidence": "/aliases"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/database_specific/severity"
  },
  "source_id": "core-osv",
  "document_id": 120737,
  "published_at": "2026-10-09T10:44:54.637+00:00"
}