{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "2.19.1"
              },
              {
                "last_affected": "2.35.1"
              }
            ],
            "source": "AFFECTED_FIELD"
          },
          "events": [
            {
              "introduced": "725192fbc0f5b289bc70a4eed451710359464ca6"
            },
            {
              "last_affected": "aacdcc47ec0b6fa778b84627c79deb7ee0cecd70"
            }
          ],
          "repo": "https://github.com/advplyr/audiobookshelf",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-pg8v-5jcv-wrvw"
  ],
  "database_specific": {
    "cna_assigner": "TuranSec",
    "cwe_ids": [
      "CWE-22"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/71xxx/CVE-2026-71209.json"
  },
  "details": "audiobookshelf's authentication-exemption check (server/routers/Auth.js) matches unauthenticated-allowed GET routes against req.path via a regex requiring a literal /items/:id/cover or /authors/:id/image shape, where req.path retains %2F sequences URL-encoded. Express's router decodes the :id route parameter before handler code runs, so a %2F-encoded '../' sequence in :id (e.g. ..%2f..%2f..%2ftmp%2fpwned) passes the literal-path auth-exemption check while resolving to a real path-traversal payload once decoded. CacheManager.handleCoverCache then joins this decoded value into a cache file path and streams the result before any database-backed ownership check. This bypasses the fix applied for CVE-2025-25205 (which anchored the exemption regex and switched it to req.path) and results in unauthenticated arbitrary file read of any file matching the pattern *_\u003cwidth\u003e[x\u003cheight\u003e].\u003cext\u003e that the service account can read.",
  "id": "CVE-2026-71209",
  "modified": "2026-08-07T11:31:25.237295078Z",
  "published": "2026-08-05T06:59:16.579Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/71xxx/CVE-2026-71209.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/advplyr/audiobookshelf/security/advisories/GHSA-pg8v-5jcv-wrvw"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-71209"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/advplyr/audiobookshelf"
    }
  ],
  "schema_version": "1.8.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "audiobookshelf: %2F Encoding Discrepancy Bypasses Cover/Image Auth Exemption Regex, Enabling Unauthenticated Path Traversal"
}