ApostropheCMS import-export tar guard misses './..' because it is a literal '../' substring test

{
  "id": "a94fe7d214047a7815b56b51a0774dbc891641cd0bc1dbc1a7ee23efd42ec304",
  "url": "https://osv.dev/vulnerability/GHSA-97wv-p4xx-c7mg",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "ApostropheCMS import-export tar guard misses './..' because it is a literal '../' substring test",
    "summary": "### Summary The tar-extraction guard added to `@apostrophecms/import-export` for GHSA-mwxc-m426-3f78 is a literal substring test for `../`, and `./..` does not contain that substring. An entry named `./..` therefore passes the guard, `path.join` normalizes it to the parent of the export directory, and the resulting `fs.WriteStream` opens a directory and emits `EISDIR` with no `error` listener attached, which terminates the Node process. Confirmed on default-branch HEAD `1bd5d0a7a6fe880836fa75adad6964f1c577d640`, package version `3.6.2`. ### Details `packages/import-export/lib/formats/gzip.js`, in the tar-stream `entry` handler inside `extract(filepath, exportPath)`: ```js const name = header.name.replace(/\\\\/g, '/'); if (name.includes('../')) { // skipped } ... stream.pipe(fs.WriteStream(path.join(exportPath, name))); ``` Two separate problems sit in those four lines. The guard tests the raw entry name for a substring instead of resolving the joined path and requiring containment, and the write stream has no `error` handler, so any stream error becomes an unhandled `'error'` event. Reaching it needs an account that can import, nothing more. `packages/import-export/modules/@apostrophecms/import-export-page/index.js` exposes `post.importExportImport`, which calls into `lib/methods/import.js`; that handler requires `req.user` and then calls `format.input(exportPath)`, which for a `.gz` upload is `gzip.js` calling `extract()` on the uploaded archive. ### PoC This is not an end-to",
    "evidence": "osv:GHSA-97wv-p4xx-c7mg",
    "products": [
      {
        "name": {
          "value": "@apostrophecms/import-export",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "3.7.0",
            "evidence": "/affected/0/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "medium",
    "structured": {
      "id": "GHSA-97wv-p4xx-c7mg",
      "aliases": [
        "CVE-2026-113664",
        "GHSA-97wv-p4xx-c7mg"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "SEMVER",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "3.7.0"
                }
              ]
            }
          ],
          "package": {
            "name": "@apostrophecms/import-export",
            "purl": "pkg:npm/%40apostrophecms/import-export",
            "ecosystem": "npm"
          },
          "database_specific": {
            "source": "https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/10/GHSA-97wv-p4xx-c7mg/GHSA-97wv-p4xx-c7mg.json"
          }
        }
      ],
      "modified": "2026-10-20T18:30:04.614026478Z",
      "provider": "osv",
      "references": [
        "https://github.com/apostrophecms/apostrophe/security/advisories/GHSA-97wv-p4xx-c7mg",
        "https://github.com/apostrophecms/apostrophe/commit/9500b8b0e1d630d5e07fbb5fd2c25ed0943845ce",
        "https://github.com/apostrophecms/apostrophe/commit/f84fd41cbf6c22eb8d0008fc9c25df1f7130b350",
        "https://github.com/apostrophecms/apostrophe",
        "https://github.com/apostrophecms/apostrophe/releases/tag/@apostrophecms/import-export@3.7.0"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-22"
        ],
        "severity": "MODERATE",
        "github_reviewed": true,
        "nvd_published_at": null,
        "github_reviewed_at": "2026-10-20T18:23:42Z"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-113664",
        "evidence": "/aliases"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 390152,
  "published_at": "2026-10-20T18:23:42+00:00"
}